// https://dashoj.com/p/98
#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

ll n, ans = -1;

int main() {
	cin >> n;
	for (ll i = 2; i * i <= n; i++) if (n % i == 0) ans = max(ans, max(i, n / i));
	if (ans == -1) cout << "YES" << endl;
	else cout << ans << endl;
	return 0;
}