#include <bits/stdc++.h>
using namespace std;

int main() {
	int n;
	cin >> n;
	bool isPrime = true; // isPrice:素数
	if (n < 2) { 
		cout << "No" << endl;
	} else {
		nn = sqrt(n);
		for (int i = 2; i <= nn; i++) {
			if (n % i == 0) {
				isPrime = false;
				break;
			}
		}
		if (isPrime) {
			cout << "Yes" << endl;
		} else {
			cout << "No" << endl;
		}
	//cout << (isPrice ? "Yes" : "No") << endl;
	}
	return 0;
}