Sum of digits in C#

Question

What\'s the fastest and easiest to read implementation of calculating the sum of digits?

I.e. Given the number: 17463 = 1 + 7 + 4 + 6 + 3 = 21

Answer 1

I use

int result = 17463.ToString().Sum(c => c - '0');

It uses only 1 line of code.