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 double pi = acos(-1.0);
inline long long read() {
  long long x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = (x << 1) + (x << 3) + ch - '0';
    ch = getchar();
  }
  return f * x;
}
inline void write(long long a) {
  if (a < 0) putchar('-'), a = -a;
  if (a >= 10) write(a / 10);
  putchar(a % 10 + '0');
}
int n;
int main() {
  cin >> n;
  long long ans = 0, last = 0;
  for (int i = 2; i < n; i++) {
    if (n % i == 0) {
      last = i;
      break;
    }
  }
  if (last)
    for (int i = 2; i < n; i++) {
      if (i * last <= n)
        for (int j = 2 * i; j <= n; j += i) {
          ans += 4LL * (j / i);
        }
    }
  cout << ans << endl;
  return 0;
}
