Factorial (n) for n > 24 is greater than 10^n.

Reminds me of: Professor asked us to find the biggest factorial using C programming language. And then using LISP. You can imagine our surprise.

Stirling's approximation is also used a lot in statistical mechanics, because you often have to calculate logs of state space sizes, which means lots of combinatorics and thus lots of factorials. Plus it's continuous so you can do calculus.

The author's casual mention of 52! at the opening of the article triggered an OLD webpage that I saw many years ago

https://czep.net/weblog/52cards.html

Anyone know how to determine the age of this page (it's got be at least 20yrs old)