Simple reversible hashing class

SimpleCrypt.php

<?php

class SimpleCrypt
{
    protected static $factor = 2 / 3 / 5 / 7 / 11 / 13 / 17 / 19 / 23 / 29;

    public static function crypt($value)
    {
        $hash = ceil($value / self::$factor);

        return $hash;
    }

    public static function decrypt($hash)
    {
        $value = floor($hash * self::$factor);

        return (int) $value;
    }
}