# include <bits/stdc++.h>
using namespace std;
long long tinh(long long n)
{
	long long ans=1,i=2;
	while(i*i<=n)
	{
		long long s=i;
		while(n%i==0) n/=i,s*=i;
		ans=ans*((s-1)/(i-1)),i++;
	}
	if(n>1) ans=ans*((n*n-1)/(n-1));
	return ans;
}
long long n;
int main()
{
	cin.tie(0)->sync_with_stdio(0);
	cin>>n;
	cout<<tinh(n);
	return 0;
}