Factorial n! of a positive integer n is defined as:
The special case 0! is defined to have value of 1: 0! = 1
This calculator below can calculate ANY factorial you want (unless you run out of computer memory to hold the resulting number), if you are willing to wait. So, go on, enter the positive integer and wait for the result. Note that you can stop calculation at any time.
Yeah, I know, big integers will be included in ES2020, but not yet, so we rely on external library. And, with big integers library, you are practically unlimited. Of course there are couple of caveats, like you have to compute factorial iteratively, otherwise you run out of stack, but technically, you are limited only by time you are willing to wait until calculation completes.