The formula is (n!/(n-r)!), where n is the things that you have and r is the amount of things you want in your set. This is assuming order matters, because (40, 19, 27, 5) is different from (5, 27, 40, 19).

So, based on that formula, you get:

44 * 43 * 42 * 41 = 3,258,024

If you have further issues with these types of problems, try this link: Combinations and Permutations