projecteuler---->problem=16----Power digit sum

215 = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26.

What is the sum of the digits of the number 21000?

翻译：

215 = 32768的各位数之和为3 + 2 + 7 + 6 + 8 = 26。

那么21000的各位数之和为……？

import math
m=pow(2,1000)
s=0
while m>0:
    s+= m%10
    m /= 10
print s