N = int(raw_input())

if N <= 2:
    print 1
    exit()
elif N == 3:
    print 4
    exit()
    
n = N
i = 2
ans = 1
while i*i <= n:
    p = 0
    while n % i == 0:
        n /= i
        p += 1
    ans *= (i ** (p + 1) - 1) / (p - 1)
    i += 1

print ans