For you math whizzes, what is 100! (Factorial)?

Answer 1

You can solve it directly...

100! = exp(sum(j = 1 to 100) {ln(j)})

or approximately using Stirling's Approximation...

100! ~= sqrt(2*pi*100) * (100/exp(1))^100

Math Rules!

Answer 2

I can't believe that you need to know the exact number, which is absolutely ginormous.

Perhaps the purpose of the exercise is just to get you to appreciate how ginormous such a number really is?

.

Answer 3

100! = 100 * 99 * 98 * ... * 3 * 2 * 1
Which equals (multiplied out):
93,326,215,443,944,152,-
681,699,238,846,266,700,-
490,715,968,264,381,621,-
468,592,963,895,217,599,-
993,229,915,608,941,463,-
976,156,518,286,253,697,-
920,827,223,758,251,185,-
210,916,864,000,000,000,-
000,000,000,000,000

93 unpentadecillion
326 pentadecillion
215 novemtetradecillion
443 octotetradecillion
...
864 septillion

Answer 4

For some reason, Yahoo refuses to display the whole thing. If you roll your mouse over the number, it will show up in a little window.

93,326,215,443,944,152,681,699,238,856,266,700,490,715,968,264,381,621,468,592,963,895,217,599,993,229,915,608,941,463,976,156,518,286,253,697,920,827,223,758,251,185,210,916,864,000,000,000,000,000,000,000,000

Answer 5

i would tell u, but im too lazy to get my calculator