I'm using ulong for the factorial of 100, but it still overflows

Question

So my task is: I have the number 100, and I have to print the sum of the digits of it\'s factorial.

So I wrote the code, found a nice way of summing the digits but my c

Answer 1

I've been playing around with my own large math research projects. You can use the .NET BigInteger class (under System.Numerics), but it's not the most efficient library out there.

If you aren't stuck on .NET, I'd suggest using the GNU Multiple Precision Arithmetic Library (https://gmplib.org/). It is both far faster and has far more functionality. You will need to study the docs to learn to use it properly.

Ports of it do exist, though I haven't seen a great port from an API perspective - do a search on Nuget.