Working with large numbers in PHP

Question

To use modular exponentiation as you would require when using the Fermat Primality Test with large numbers (100,000+), it calls for some very large calculations.

Whe

Answer 1

I wrote a very small code for you that will surely work in case of big numbers-

";
    echo "mod : ".$mod;

    /* Output:
        x : 3915505476
        mod : 2968
    */
?>

You simply have to use strings for storing big numbers and to operate on them use GMP functions in PHP.

You may check some good GMP functions in the official PHP manual here- http://php.net/manual/en/ref.gmp.php