Project Euler解答21~25

#-*- coding:utf-8 -*-
#Euler21
TOTAL=0
N=10000

def divisor_sum(x):
	b=0
	for i in range(1,x):
		if x % i == 0:
			b+=i
	return b

if __name__=="__main__":
	for a in range(1,N):
		if divisor_sum(divisor_sum(a))==a and a != divisor_sum(a):
				TOTAL+=a
	print TOTAL