28237
 13190
 39914
 81367
 8554
 61106
 67448
 39004
 22308
 16054
 71468
 60501
 100
 300
 59632
 90783
 5611
 1000
 69475
 69753
 10
 5
 582
 8
 36961
 5071
 20
 53213
 92775
 28738
 100000
 92280
 37944
 9
 2627
 7
 3

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#include <bits/stdc++.h>

using namespace std;

#define forn(i, x, n) for (int i = int(x); i <= int(n); ++i)
#define for1(i, n, x) for (int i = int(n); i >= int(x); --i)
#define x first
#define y second
#define pb push_back

typedef long long ll;
typedef pair <ll, ll> pii;
typedef long double ld;
typedef vector <int> vi;

const int N = 2e6 + 10;
const int INF = 1e9 + 9;
const int B = 1e9 + 7;

int main() {
    #ifdef black
    freopen("in", "r", stdin);
    #endif // black
    ios_base :: sync_with_stdio(0);
    cin.tie(0);

    int n;
    cin >> n;
    vector <ll> a(n + 1);
    ll ans = 0;
    ll cur = 1;
    for1(i, n, 2) {
        for (int j = 2; i * j <= n; ++j)
            a[i] += a[i * j] + 4 * j;
    //    cerr << i << ": " << a[i] << "\n";
    }
    forn(i, 2, n) {
        if (__gcd(1ll * i, cur) != 1) continue;
        if (a[i] == 0) break;
        ans += a[i];
        cur *= i;
    }
    cout << ans << "\n";

    return 0;
}

