Factorial Trailing Digits 2

For any $N$ , let $f (N)$ be the last twelve hexadecimal digits before the trailing zeroes in $N!$ .

For example, the hexadecimal representation of $20!$ is 21C3677C82B40000,
so $f (20)$ is the digit sequence 21C3677C82B4.

Find $f (20!)$ . Give your answer as twelve hexadecimal digits, using uppercase for the digits A to F.

Write-up coming later

The complete problem is available here. An approach, code, and answer will be added later.