def prime_factorization(n):  # 素因数分解
    res = []
    for i in range(2, int(n ** 0.5) + 1):
        if n % i == 0:
            cnt = 0
            while n % i == 0:
                cnt += 1
                n //= i
            res.append((i, cnt))
    if n > 1:
        res.append((n, 1))
    return res


N = int(input())
pf = prime_factorization(N)

ans = 1
for p, f in pf:
    v = (p ** (f + 1) - 1) // (p - 1)
    ans *= v

print(ans)