N = int(input())
ans = 1
x = 2
while x*x <= N:
    if N % x == 0:
        c = 1
        while N % x == 0:
            N //= x
            c += 1
        ans *= (x**c - 1)//(x-1)
    x += 1
if N > 1:
    ans *= 1 + N
print(ans)