#include<cstdio>

#include<algorithm>

#include<cmath>

#include<string>

using namespace std;

typedef long long ll;

void setIO(string a){freopen((a+".in").c_str(),"r",stdin);}

int main(){

	//setIO("input");

	ll n,ans;

	while(scanf("%lld",&n)!=EOF){

		ans=n;

		for(ll i=2;i<=(ll)sqrt(n*1.0);++i){

			int a=i;

			if(n%i==0)

			{

				int p=0;

				while(n%i==0){

					++p;

					n/=i;

				}

				ans+=ans*p*(a-1)/a;

			}

		}

		if(n!=1) ans+=ans*(n-1)/n;

		printf("%lld\n",ans);

	}

	return 0;

}