Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/MathTrig.php
public static function EVEN($number)
    {
        $number = Functions::flattenSingleValue($number);

        if ($number === null) {
            return 0;
        } elseif (is_bool($number)) {
            $number = (int) $number;
        }

        if (is_numeric($number)) {
            $significance = 2 * self::SIGN($number);

            return (int) self::CEILING($number, $significance);
        }

        return Functions::VALUE();
    }
public static function EVEN($number)
    {
        $number = Functions::flattenSingleValue($number);

        if ($number === null) {
            return 0;
        } elseif (is_bool($number)) {
            $number = (int) $number;
        }

        if (is_numeric($number)) {
            $significance = 2 * self::SIGN($number);

            return (int) self::CEILING($number, $significance);
        }

        return Functions::VALUE();
    }
EVEN.

Returns number rounded up to the nearest even integer.
You can use this function for processing items that come in twos. For example,
a packing crate accepts rows of one or two items. The crate is full when
the number of items, rounded up to the nearest two, matches the crate's
capacity.

Excel Function:
EVEN(number)

@category Mathematical and Trigonometric Functions

@param float $number Number to round

@return int Rounded Number