Project Euler 20

• 問題

Problem 20：Factorial digit sum
n! means n × (n − 1) × ... × 3 × 2 × 1

For example, 10! = 10 × 9 × ... × 3 × 2 × 1 = 3628800,
and the sum of the digits in the number 10! is 3 + 6 + 2 + 8 + 8 + 0 + 0 = 27.

Find the sum of the digits in the number 100!

• 解答例

import math

strNum = str(math.factorial(100))

sum = 0
for i in strNum:
    sum += int(i)

print(sum)