PHP Calculate factorial of a number!!

We can easily calculate factorial of a number.

<?php
function factorial($n){

if($n<1) $n = 1;

return array_product(range(1,$n));

}
?>

Friends please share with me like such easier PHP related programs.
Thanks.

Mahamrityunjaya Mantra

Om Tryambakam Yajamahe
Sugandhim Pushtivardhanam
Urvarukamiva Bandhanan
Mrityor Mukshiya Maamritat

Meaning: We Meditate on the Three-eyed reality
Which permeates and nourishes all like a fragrance. 
May we be liberated from death for the sake of immortality, 
Even as the cucumber is severed from bondage to the creeper.