#include <bits/stdc++.h>
using namespace std;

map<int64_t, int64_t> prime_division(int64_t n){
    map<int64_t, int64_t> ret;
    for(int64_t i=2; i*i<=n; i++){
        while(n % i == 0){
            n /= i;
            ret[i]++;
        }
    }
    if(n > 1) ret[n] = 1;
    return ret;
}

int main() {
    int64_t N;
    cin >> N;
    auto ps = prime_division(N);
    int64_t ans = 1;
    for(auto& pr : ps){
        int64_t p = pr.first, num = pr.second;
        int64_t P = 1;
        for(int i=0; i<=num; i++) P *= p;
        ans *= (P-1)/(p-1);
    }
    cout << ans << endl;
    return 0;
}