how to calculate right most non zero digit in 133 !

rightmost non zero digit cam found out by the formula:
let the Number be N==> N! => find the remainder of below expression divided by 10 or just find its unit didgit:
[N/5]! * 2^(N/5) *[ [N/5](remainder)]

repeat the steps..and you can find the ans:
[113/5)! * 2^9113/5) * (remainder of 113/5)!
22! * 2^22 * 3!
repeat for 22! and continue.