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

ll tinh(ll n)
{
	ll ok=1, i=2, s;
	while(i*i<=n)
	{
        if(n%i==0)
        {
            s = i;
            while(n%i==0) {n/=i; s*=i;}
            ok = ok*(s-1)/(i-1);
        }
        ++i;
	}
	if(n>1) ok = ok*(n*n-1)/(n-1);
	return ok;
}

ll n;
int main()
{
	cin.tie(0)->sync_with_stdio(0);
	cin >> n;
	cout << tinh(n);
	return 0;
}