Project Euler/20

Sum of Factorial Digits

For this problem, you're asked to sum the digits of 100!. This is a very quick task using a library like BigInteger - the Go programming language also has the facilities built-in to handle numbers as large as 800!.

https://charlesreid1.com:3000/charlesreid1/hello-world/src/master/go/factorial.go

To do this in Java, you can use the Big Integer class, convert it to a String, and then turn the characters in the string into digits one at a time to sum them up.