How to calculate password strength?

Question

Mathematics

I have a password consisting of unique (non-repeating) characters.
The password is generated by shuffling the characters in the pattern.
For example,
Template: 'abcdefghijklmnopqrstuvwxyz1234567890'
Password: 'ql91cnrim8d2jh4a6s3exof5pk0bgu7tzvwy'
What formula can be used to calculate the number of possible combinations if the template is known?

Answer 1

Number of permutations of N elements = N! (N-factorial)