import math
import collections

def factorize(n):
    ''' returns a list of prime factors of n.
    ex. factorize(24) = [2, 2, 2, 3]
    source: Rossetta code: prime factorization (slightly modified)
    http://rosettacode.org/wiki/Prime_decomposition#Python:_Using_floating_point
    '''
    step = lambda x: 1 + (x<<2) - ((x>>1)<<1)
    maxq = int(math.floor(math.sqrt(n)))
    d = 1
    q = n % 2 == 0 and 2 or 3
    while q <= maxq and n % q != 0:
        q = step(d)
        d += 1
    return q <= maxq and [q] + factorize(n//q) or [n]

def sum_of_divisors(n):
    ''' returns the sum of divisors of integer n.
    n must be a positive integer.
    the sum includes n itself.
    ex. sum_of_divisors(6) = 6 + 3 + 2 + 1 = 12
    '''
    if n == 1:
        return 1
    factors = collections.Counter(factorize(n))
    result = 1
    for p, a in factors.items():
        result *= (p ** (a + 1) - 1)//(p - 1)
    return result

N = int(input())
if N & 1:
    print(sum_of_divisors(N))
else:
    print(sum_of_divisors(N//2))