#include <map>
#include <set>
#include <array>
#include <cmath>
#include <deque>
#include <bitset>
#include <random>
#include <string>
#include <vector>
#include <cassert>
#include <complex>
#include <iomanip>
#include <iostream>
#include <algorithm>
#include <unordered_map>
#include <unordered_set>

using namespace std;

#define int int64_t


signed main() {
#ifdef DEBUG
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
#else
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
#endif

  int x;
  cin >> x;
  if (x == 1) {
    cout << "1\n";
    return 0;
  }
  vector<array<int, 2>> prm;
  for (int i = 2; i * i * i <= x; ++i) {
    if (x % i == 0) {
      int cnt = 0;
      while (x % i == 0) {
        ++cnt;
        x /= i;
      }
      prm.push_back({i, cnt});
    }
  }

  if (x != 1) {
    int p = sqrt(x);
    while (p * p > x) --p;
    while ((p + 1) * (p + 1) <= x) ++p;
    if (p * p != x) {
      cout << "-1\n";
      return 0;
    }
    prm.push_back({p, 2});
  }
  
  int g = 0;
  for (auto elem : prm) {
    g = __gcd(g, elem[1]);
  }

  for (int i = g; i >= 2; --i) {
    if (g % i != 0) continue;
    int chk = 1;
    for (auto elem : prm) {
      chk *= (elem[1] / i + 1);
    }
    if (chk == i) {
      int n = 1;
      for (auto elem : prm) {
        for (int t = 0; t < elem[1] / i; ++t) {
          n *= elem[0];
        }
      }
      cout << n << "\n";
      return 0;
    }
  }
  cout << "-1\n";

  return 0;
}