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;
const int maxn = 1e5 + 7;
const int inf = 1e9 + 7;
int vis[maxn], cnt[maxn], n;
int main() {
  vis[0] = 1;
  vis[1] = 1;
  int t = 0;
  for (int i = 2; i < maxn - 5; i++) {
    if (!vis[i]) cnt[t++] = i;
    for (int j = 0; j < t && i * cnt[j] < maxn - 5; j++) {
      vis[i * cnt[j]] = 1;
      if (i % cnt[j] == 0) break;
    }
  }
  cin >> n;
  long long ans = 0;
  for (int i = 0; i < t; i++) {
    if (n >= cnt[i] && n % cnt[i] == 0) {
      if (n / cnt[i] == 1) break;
      int l, r;
      if (n / cnt[i] <= cnt[i]) {
        l = 2;
        r = n / cnt[i];
      } else {
        l = cnt[i];
        r = n / cnt[i];
      }
      ans += (l + r) * 2 * (r - l + 1);
    }
  }
  cout << ans << endl;
  return 0;
}
