data/problems/20.yml
---
:id: 20
:name: Factorial digit sum
:url: https://projecteuler.net/problem=20
:content: "_n_! means _n_ × (_n_ − 1) × ... × 3 × 2 × 1\n\nFor example, 10! = 10 ×
9 × ... × 3 × 2 × 1 = 3628800, \nand the sum of the digits in the number 10! is
3 + 6 + 2 + 8 + 8 + 0 + 0 = 27.\n\nFind the sum of the digits in the number 100!\n\n"