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

template <typename T>
struct PrimeSieve{
    int n, half;
    std::vector<bool> sieve;
    std::vector<T> prime_list;
    // sieve[i] ... 2 * i + 1

    PrimeSieve(T _n) : n(_n){
        init();
    }

    void init(){
        if(n < 2){
            return;
        }
        half = (n + 1) / 2;
        sieve.assign(half, true);
        sieve[0] = false;
        prime_list.emplace_back(2);
        for(long long i = 1; 2 * i + 1 <= n; ++i){
            if(!sieve[i]) continue;
            T p = 2 * i + 1;
            prime_list.emplace_back(p);
            for(long long j = 2 * i * (i + 1); j < half; j += p){
                sieve[j] = false;
            }
        }
    }

    bool isPrime(T x){
        if(x == 2) return true;
        if(x % 2 == 0) return false;
        return sieve[x / 2];
    }

    T getPrimeCount(){
        return prime_list.size();
    }

    T getKthPrime(int k){
        return prime_list[k];
    }
};

int main(){
    long long n; cin >> n;
    assert(2LL <= n && n <= 10000000000LL);

    const int MAX_SQRT = 100000;
    PrimeSieve<int> ps(MAX_SQRT);

    long long ans = 0;
    for(long long i = 2; i * i <= n; i++){
        if(!ps.isPrime(i)) continue;
        for(long long j = i * i; j <= n; j *= i){
            ans += j;
        }
    }
    cout << ans << endl;
}