include <bits/stdc++.h>

using namespace std; int main(){

int n;
cin >> n;
if(n < 2){
	cout << "No" << endl;
	return 0;
}
int t = sqrt(n);
for(int i = 2; i <= t; i++){
	if(n % i == 0){
		cout << "No" << endl;
		return 0;
	}
}
cout << "Yes" << endl;
return 0;

}