#include<bits/stdc++.h>
typedef long long ll;
using namespace std;
int INF = 1e9;
int MOD = 1e9+7;
ll N;
bool judge(int count,ll num){
    if(count == 2)return (num != 1);
    if(num % 2 == 0)return judge(count+1,num/2);
    for(ll i = 3;i*i <= N && i <= num;i++){
        if(num % i == 0)return judge(count+1,num/i);
    }
    return false;
}
main(){
    cin >> N;
    if(judge(0,N))cout << "YES" << endl;
    else cout << "NO" << endl;
}