diff --git a/src/PhpSpreadsheet/Calculation/Engineering/BitWise.php b/src/PhpSpreadsheet/Calculation/Engineering/BitWise.php
index e1ace4f313..c861c21a01 100644
--- a/src/PhpSpreadsheet/Calculation/Engineering/BitWise.php
+++ b/src/PhpSpreadsheet/Calculation/Engineering/BitWise.php
@@ -36,7 +36,7 @@ private static function splitNumber(float|int $number): array
      * @return array|int|string If an array of numbers is passed as an argument, then the returned result will also be an array
      *            with the same dimensions
      */
-    public static function BITAND(null|array|bool|float|int|string $number1, null|array|bool|float|int|string $number2): array|string|int
+    public static function BITAND(null|array|bool|float|int|string $number1, null|array|bool|float|int|string $number2): array|string|int|float
     {
         if (is_array($number1) || is_array($number2)) {
             return self::evaluateArrayArguments([self::class, __FUNCTION__], $number1, $number2);
@@ -68,7 +68,7 @@ public static function BITAND(null|array|bool|float|int|string $number1, null|ar
      * @return array|int|string If an array of numbers is passed as an argument, then the returned result will also be an array
      *            with the same dimensions
      */
-    public static function BITOR(null|array|bool|float|int|string $number1, null|array|bool|float|int|string $number2): array|string|int
+    public static function BITOR(null|array|bool|float|int|string $number1, null|array|bool|float|int|string $number2): array|string|int|float
     {
         if (is_array($number1) || is_array($number2)) {
             return self::evaluateArrayArguments([self::class, __FUNCTION__], $number1, $number2);
@@ -101,7 +101,7 @@ public static function BITOR(null|array|bool|float|int|string $number1, null|arr
      * @return array|int|string If an array of numbers is passed as an argument, then the returned result will also be an array
      *            with the same dimensions
      */
-    public static function BITXOR(null|array|bool|float|int|string $number1, null|array|bool|float|int|string $number2): array|string|int
+    public static function BITXOR(null|array|bool|float|int|string $number1, null|array|bool|float|int|string $number2): array|string|int|float
     {
         if (is_array($number1) || is_array($number2)) {
             return self::evaluateArrayArguments([self::class, __FUNCTION__], $number1, $number2);
diff --git a/src/PhpSpreadsheet/Chart/Axis.php b/src/PhpSpreadsheet/Chart/Axis.php
index 1d27c8b402..b83795858b 100644
--- a/src/PhpSpreadsheet/Chart/Axis.php
+++ b/src/PhpSpreadsheet/Chart/Axis.php
@@ -84,6 +84,7 @@ public function __construct()
     public const DISP_UNITS_HUNDRED_MILLIONS = 'hundredMillions';
     public const DISP_UNITS_BILLIONS = 'billions';
     public const DISP_UNITS_TRILLIONS = 'trillions';
+    public const TRILLION_INDEX = (PHP_INT_SIZE > 4) ? 1000000000000 : '1000000000000';
     public const DISP_UNITS_BUILTIN_INT = [
         100 => self::DISP_UNITS_HUNDREDS,
         1000 => self::DISP_UNITS_THOUSANDS,
@@ -93,7 +94,7 @@ public function __construct()
         10000000 => self::DISP_UNITS_TEN_MILLIONS,
         100000000 => self::DISP_UNITS_HUNDRED_MILLIONS,
         1000000000 => self::DISP_UNITS_BILLIONS,
-        1000000000000 => self::DISP_UNITS_TRILLIONS,
+        self::TRILLION_INDEX => self::DISP_UNITS_TRILLIONS, // overflow for 32-bit
     ];
 
     /**
diff --git a/src/PhpSpreadsheet/Reader/Xls.php b/src/PhpSpreadsheet/Reader/Xls.php
index a54105a3b4..36c7072441 100644
--- a/src/PhpSpreadsheet/Reader/Xls.php
+++ b/src/PhpSpreadsheet/Reader/Xls.php
@@ -67,6 +67,10 @@
 //         external sheet reference structure
 class Xls extends BaseReader
 {
+    private const HIGH_ORDER_BIT = 0x80 << 24;
+    private const FC000000 = 0xFC << 24;
+    private const FE000000 = 0xFE << 24;
+
     // ParseXL definitions
     const XLS_BIFF8 = 0x0600;
     const XLS_BIFF7 = 0x0500;
@@ -2150,8 +2154,8 @@ private function readXf(): void
                 // bit: 30; mask: 0x40000000; 1 = diagonal line from top left to right bottom
                 $diagonalDown = (0x40000000 & self::getInt4d($recordData, 10)) >> 30 ? true : false;
 
-                // bit: 31; mask: 0x80000000; 1 = diagonal line from bottom left to top right
-                $diagonalUp = ((int) 0x80000000 & self::getInt4d($recordData, 10)) >> 31 ? true : false;
+                // bit: 31; mask: 0x800000; 1 = diagonal line from bottom left to top right
+                $diagonalUp = (self::HIGH_ORDER_BIT & self::getInt4d($recordData, 10)) >> 31 ? true : false;
 
                 if ($diagonalUp === false) {
                     if ($diagonalDown === false) {
@@ -2181,7 +2185,7 @@ private function readXf(): void
                 }
 
                 // bit: 31-26; mask: 0xFC000000 fill pattern
-                if ($fillType = Xls\Style\FillPattern::lookup(((int) 0xFC000000 & self::getInt4d($recordData, 14)) >> 26)) {
+                if ($fillType = Xls\Style\FillPattern::lookup((self::FC000000 & self::getInt4d($recordData, 14)) >> 26)) {
                     $objStyle->getFill()->setFillType($fillType);
                 }
                 // offset: 18; size: 2; pattern and background colour
@@ -2233,7 +2237,7 @@ private function readXf(): void
                 $objStyle->getBorders()->getBottom()->setBorderStyle(Xls\Style\Border::lookup((0x01C00000 & $borderAndBackground) >> 22));
 
                 // bit: 31-25; mask: 0xFE000000; bottom line color
-                $objStyle->getBorders()->getBottom()->colorIndex = ((int) 0xFE000000 & $borderAndBackground) >> 25;
+                $objStyle->getBorders()->getBottom()->colorIndex = (self::FE000000 & $borderAndBackground) >> 25;
 
                 // offset: 12; size: 4; cell border lines
                 $borderLines = self::getInt4d($recordData, 12);
@@ -7184,10 +7188,10 @@ private static function extractNumber(string $data): int|float
     {
         $rknumhigh = self::getInt4d($data, 4);
         $rknumlow = self::getInt4d($data, 0);
-        $sign = ($rknumhigh & (int) 0x80000000) >> 31;
+        $sign = ($rknumhigh & self::HIGH_ORDER_BIT) >> 31;
         $exp = (($rknumhigh & 0x7FF00000) >> 20) - 1023;
         $mantissa = (0x100000 | ($rknumhigh & 0x000FFFFF));
-        $mantissalow1 = ($rknumlow & (int) 0x80000000) >> 31;
+        $mantissalow1 = ($rknumlow & self::HIGH_ORDER_BIT) >> 31;
         $mantissalow2 = ($rknumlow & 0x7FFFFFFF);
         $value = $mantissa / 2 ** (20 - $exp);
 
@@ -7195,7 +7199,9 @@ private static function extractNumber(string $data): int|float
             $value += 1 / 2 ** (21 - $exp);
         }
 
-        $value += $mantissalow2 / 2 ** (52 - $exp);
+        if ($mantissalow2 != 0) {
+            $value += $mantissalow2 / 2 ** (52 - $exp);
+        }
         if ($sign) {
             $value *= -1;
         }
@@ -7213,7 +7219,7 @@ private static function getIEEE754(int $rknum): float|int
             // The RK format calls for using only the most significant 30 bits
             // of the 64 bit floating point value. The other 34 bits are assumed
             // to be 0 so we use the upper 30 bits of $rknum as follows...
-            $sign = ($rknum & (int) 0x80000000) >> 31;
+            $sign = ($rknum & self::HIGH_ORDER_BIT) >> 31;
             $exp = ($rknum & 0x7FF00000) >> 20;
             $mantissa = (0x100000 | ($rknum & 0x000FFFFC));
             $value = $mantissa / 2 ** (20 - ($exp - 1023));
diff --git a/src/PhpSpreadsheet/Shared/OLE/PPS.php b/src/PhpSpreadsheet/Shared/OLE/PPS.php
index 564fe7ec7c..d67dbd6df1 100644
--- a/src/PhpSpreadsheet/Shared/OLE/PPS.php
+++ b/src/PhpSpreadsheet/Shared/OLE/PPS.php
@@ -29,6 +29,8 @@
  */
 class PPS
 {
+    private const ALL_ONE_BITS = (PHP_INT_SIZE > 4) ? 0xFFFFFFFF : -1;
+
     /**
      * The PPS index.
      */
@@ -178,14 +180,14 @@ public function getPpsWk(): string
     public static function savePpsSetPnt(array &$raList, mixed $to_save, mixed $depth = 0): int
     {
         if (!is_array($to_save) || (empty($to_save))) {
-            return 0xFFFFFFFF;
+            return self::ALL_ONE_BITS;
         } elseif (count($to_save) == 1) {
             $cnt = count($raList);
             // If the first entry, it's the root... Don't clone it!
             $raList[$cnt] = ($depth == 0) ? $to_save[0] : clone $to_save[0];
             $raList[$cnt]->No = $cnt;
-            $raList[$cnt]->PrevPps = 0xFFFFFFFF;
-            $raList[$cnt]->NextPps = 0xFFFFFFFF;
+            $raList[$cnt]->PrevPps = self::ALL_ONE_BITS;
+            $raList[$cnt]->NextPps = self::ALL_ONE_BITS;
             $raList[$cnt]->DirPps = self::savePpsSetPnt($raList, @$raList[$cnt]->children, $depth++);
         } else {
             $iPos = (int) floor(count($to_save) / 2);
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/Chart.php b/src/PhpSpreadsheet/Writer/Xlsx/Chart.php
index c89696ac9e..1e96db305d 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/Chart.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/Chart.php
@@ -968,7 +968,7 @@ private function writeValueAxis(XMLWriter $objWriter, ?Title $yAxisLabel, ?strin
 
             if ($xAxis->getAxisType() === Axis::AXIS_TYPE_VALUE) {
                 $dispUnits = $xAxis->getAxisOptionsProperty('dispUnitsBuiltIn');
-                $dispUnits = is_numeric($dispUnits) ? (Axis::DISP_UNITS_BUILTIN_INT[(int) $dispUnits] ?? '') : $dispUnits;
+                $dispUnits = ($dispUnits == Axis::TRILLION_INDEX) ? Axis::DISP_UNITS_TRILLIONS : (is_numeric($dispUnits) ? (Axis::DISP_UNITS_BUILTIN_INT[(int) $dispUnits] ?? '') : $dispUnits);
                 if (in_array($dispUnits, Axis::DISP_UNITS_BUILTIN_INT, true)) {
                     $objWriter->startElement('c:dispUnits');
                     $objWriter->startElement('c:builtInUnit');
diff --git a/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/BitAndTest.php b/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/BitAndTest.php
index ed3ba55629..1f913cbed8 100644
--- a/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/BitAndTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/BitAndTest.php
@@ -16,7 +16,7 @@ class BitAndTest extends TestCase
     /**
      * @dataProvider providerBITAND
      */
-    public function testDirectCallToBITAND(mixed $expectedResult, null|bool|int|float|string $arg1, null|bool|int|float|string $arg2): void
+    public function testDirectCallToBITAND(float|int|string $expectedResult, null|bool|int|float|string $arg1, null|bool|int|float|string $arg2): void
     {
         $result = BitWise::BITAND($arg1, $arg2);
         self::assertSame($expectedResult, $result);
@@ -25,7 +25,7 @@ public function testDirectCallToBITAND(mixed $expectedResult, null|bool|int|floa
     /**
      * @dataProvider providerBITAND
      */
-    public function testBITANDAsFormula(mixed $expectedResult, mixed ...$args): void
+    public function testBITANDAsFormula(float|int|string $expectedResult, mixed ...$args): void
     {
         $arguments = new FormulaArguments(...$args);
 
@@ -39,7 +39,7 @@ public function testBITANDAsFormula(mixed $expectedResult, mixed ...$args): void
     /**
      * @dataProvider providerBITAND
      */
-    public function testBITANDInWorksheet(mixed $expectedResult, mixed ...$args): void
+    public function testBITANDInWorksheet(float|int|string $expectedResult, mixed ...$args): void
     {
         $arguments = new FormulaArguments(...$args);
 
diff --git a/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/BitOrTest.php b/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/BitOrTest.php
index 9471f27d25..f27f731f3c 100644
--- a/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/BitOrTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/BitOrTest.php
@@ -16,7 +16,7 @@ class BitOrTest extends TestCase
     /**
      * @dataProvider providerBITOR
      */
-    public function testDirectCallToBITOR(mixed $expectedResult, null|bool|int|float|string $arg1, null|bool|int|float|string $arg2): void
+    public function testDirectCallToBITOR(float|int|string $expectedResult, null|bool|int|float|string $arg1, null|bool|int|float|string $arg2): void
     {
         $result = BitWise::BITOR($arg1, $arg2);
         self::assertSame($expectedResult, $result);
@@ -25,7 +25,7 @@ public function testDirectCallToBITOR(mixed $expectedResult, null|bool|int|float
     /**
      * @dataProvider providerBITOR
      */
-    public function testBITORAsFormula(mixed $expectedResult, mixed ...$args): void
+    public function testBITORAsFormula(float|int|string $expectedResult, mixed ...$args): void
     {
         $arguments = new FormulaArguments(...$args);
 
@@ -39,7 +39,7 @@ public function testBITORAsFormula(mixed $expectedResult, mixed ...$args): void
     /**
      * @dataProvider providerBITOR
      */
-    public function testBITORInWorksheet(mixed $expectedResult, mixed ...$args): void
+    public function testBITORInWorksheet(float|int|string $expectedResult, mixed ...$args): void
     {
         $arguments = new FormulaArguments(...$args);
 
diff --git a/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/BitXorTest.php b/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/BitXorTest.php
index a9e6489b9c..1c42c0f041 100644
--- a/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/BitXorTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/BitXorTest.php
@@ -16,7 +16,7 @@ class BitXorTest extends TestCase
     /**
      * @dataProvider providerBITXOR
      */
-    public function testDirectCallToBITXOR(int|string $expectedResult, null|bool|int|float|string $arg1, null|bool|int|float|string $arg2): void
+    public function testDirectCallToBITXOR(float|int|string $expectedResult, null|bool|int|float|string $arg1, null|bool|int|float|string $arg2): void
     {
         $result = BitWise::BITXOR($arg1, $arg2);
         self::assertSame($expectedResult, $result);
@@ -25,7 +25,7 @@ public function testDirectCallToBITXOR(int|string $expectedResult, null|bool|int
     /**
      * @dataProvider providerBITXOR
      */
-    public function testBITXORAsFormula(mixed $expectedResult, mixed ...$args): void
+    public function testBITXORAsFormula(float|int|string $expectedResult, mixed ...$args): void
     {
         $arguments = new FormulaArguments(...$args);
 
@@ -39,7 +39,7 @@ public function testBITXORAsFormula(mixed $expectedResult, mixed ...$args): void
     /**
      * @dataProvider providerBITXOR
      */
-    public function testBITXORInWorksheet(mixed $expectedResult, mixed ...$args): void
+    public function testBITXORInWorksheet(float|int|string $expectedResult, mixed ...$args): void
     {
         $arguments = new FormulaArguments(...$args);
 
diff --git a/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/ImExpTest.php b/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/ImExpTest.php
index a6834310ca..4ecfa1a884 100644
--- a/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/ImExpTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/Functions/Engineering/ImExpTest.php
@@ -15,7 +15,7 @@
 
 class ImExpTest extends TestCase
 {
-    const COMPLEX_PRECISION = 1E-12;
+    const COMPLEX_PRECISION = (PHP_INT_SIZE > 4) ? 1E-12 : 1E-9;
 
     private \PhpOffice\PhpSpreadsheetTests\Custom\ComplexAssert $complexAssert;
 
diff --git a/tests/PhpSpreadsheetTests/Chart/Issue3833Test.php b/tests/PhpSpreadsheetTests/Chart/Issue3833Test.php
index 669e23306f..efd7c5f939 100644
--- a/tests/PhpSpreadsheetTests/Chart/Issue3833Test.php
+++ b/tests/PhpSpreadsheetTests/Chart/Issue3833Test.php
@@ -4,6 +4,7 @@
 
 namespace PhpOffice\PhpSpreadsheetTests\Chart;
 
+use PhpOffice\PhpSpreadsheet\Chart\Axis;
 use PhpOffice\PhpSpreadsheet\Reader\Xlsx as XlsxReader;
 use PhpOffice\PhpSpreadsheet\Writer\Xlsx as XlsxWriter;
 use PhpOffice\PhpSpreadsheetTests\Functional\AbstractFunctional;
@@ -136,6 +137,11 @@ public function testLogBase(): void
         self::assertSame('10', $logBase);
         $dispUnits = $yAxis->getAxisOptionsProperty('dispUnitsBuiltIn');
         self::assertNull($dispUnits);
+        $yAxis->setAxisOption('dispUnitsBuiltIn', 1000000000000);
+        $dispUnits = $yAxis->getAxisOptionsProperty('dispUnitsBuiltIn');
+        // same logic as in Writer/Xlsx/Chart for 32-bit safety
+        $dispUnits = ($dispUnits == Axis::TRILLION_INDEX) ? Axis::DISP_UNITS_TRILLIONS : (is_numeric($dispUnits) ? (Axis::DISP_UNITS_BUILTIN_INT[(int) $dispUnits] ?? '') : $dispUnits);
+        self::assertSame('trillions', $dispUnits);
 
         $reloadedSpreadsheet->disconnectWorksheets();
     }
diff --git a/tests/PhpSpreadsheetTests/Shared/DateTest.php b/tests/PhpSpreadsheetTests/Shared/DateTest.php
index f4f1256889..8da86e98ee 100644
--- a/tests/PhpSpreadsheetTests/Shared/DateTest.php
+++ b/tests/PhpSpreadsheetTests/Shared/DateTest.php
@@ -170,7 +170,7 @@ public static function providerIsDateTimeFormatCode(): array
     /**
      * @dataProvider providerDateTimeExcelToTimestamp1900Timezone
      */
-    public function testDateTimeExcelToTimestamp1900Timezone(int $expectedResult, float|int $excelDateTimeValue, string $timezone): void
+    public function testDateTimeExcelToTimestamp1900Timezone(float|int $expectedResult, float|int $excelDateTimeValue, string $timezone): void
     {
         if (is_numeric($expectedResult) && ($expectedResult > PHP_INT_MAX || $expectedResult < PHP_INT_MIN)) {
             self::markTestSkipped('Test invalid on 32-bit system.');