import math
def sieve(n):
	prime = []
	p = 2
	for p in xrange(2,int(math.sqrt(n))+2):
		mul = 0
		while n % p == 0:
			mul += 1
			n /= p
		if mul != 0:
			prime.append([p,mul])
	if n != 1:
		prime.append([n,1])
	return prime
N = input()
X = N>>(N&1^1)
ans = 1
for p,m in sieve(X):
	ans *= (p**(m+1)-1)/(p-1)
print ans