PHP | gmp_fact() for large factorials (original) (raw)

Last Updated : 11 Jul, 2025

The gmp_fact() is a built-in function in PHP which is used to calculate the factorial of a GMP number (GNU Multiple Precision : For large numbers).Syntax:

gmp_fact ( $num )

Parameters: This function accepts a GMP number as a mandatory parameter as shown in the above syntax. It can be a GMP object in PHP version 5.6 and later, or a numeric string provided that it is possible to convert the latter to a number.This function calculates the factorial of this number and returns it.Return Value: This function returns a GMP number which is the factorial of the number passed as parameter. Examples:

Input : "9" Output : 362880

Input : 25 Output : 15511210043330985984000000

Below programs illustrate the gmp_fact() function in PHP :Program 1:

php `

`

Output:

120

Program 2:

php `

`

Output:

15511210043330985984000000

Reference: https://www.php.net/manual/en/function.gmp-fact.php