#include <iostream>
#include <math.h>
using namespace std;

#define fastcin {\
    cin.tie(0);\
    ios::sync_with_stdio(false);\
}
#define rep(i, a, b) for(int i = a; i < b; ++i)
#define scan(x) cin >> x
#define print(x) cout << x << "\n"


int main() {
    fastcin;
    long N; scan(N);
    auto sq = (int)sqrt(N);
    bool flag = false, p[sq+1];
    int k;
    rep(i, 2, sq+1) p[i] = true;
    rep(i, 2, sq+1) {
        if (p[i]) {
            k = i;
            while (k!=N && !(N%k)) {
                if (flag) {
                    print("YES");
                    return 0;
                }
                flag = true;
                k *= k;
            }
            for (int j = i<<1; j < sq+1; j+=i) p[j] = false;
        }
    }
    print("NO");
    return 0;
}