GMP Functions
PHP Manual

gmp_fact

Factorial

Description

resource gmp_fact ( mixed $a )

Calculates factorial (a!) of a.

Parameters

a

The factorial number.

It can be either a GMP number resource, or a numeric string given that it is possible to convert the latter to a number.

Return Values

A GMP number resource.

Examples

Example #1 gmp_fact example

<?php
$fact1 = gmp_fact(5); // 5 * 4 * 3 * 2 * 1
echo gmp_strval($fact1) . "\n";

$fact2 = gmp_fact(50); // 50 * 49 * 48, ... etc
echo gmp_strval($fact2) . "\n";
?>

The above example will output:

120
30414093201713378043612608166064768844377641568960512000000000000