#include <iostream>
using namespace std;

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

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        if (n < 2) {
            System.out.println("No");
            return;
        }
        for (long i = 2; i * i <= n; i++) {
            if (n % i == 0) {
                System.out.println("No");
                return;
            }
        }
        System.out.println("Yes");
    }
}

import math

n = int(input())
if n < 2:
    print("No")
else:
    is_prime = True
    for i in range(2, int(math.isqrt(n)) + 1):
        if n % i == 0:
            is_prime = False
            break
    print("Yes" if is_prime else "No")

const readline = require('readline');
const rl = readline.createInterface({ input: process.stdin });
const lines = [];
rl.on('line', line => lines.push(line));
rl.on('close', () => {
    const n = BigInt(lines[0].trim());
    if (n < 2n) {
        console.log("No");
        return;
    }
    let isPrime = true;
    for (let i = 2n; i * i <= n; i++) {
        if (n % i === 0n) {
            isPrime = false;
            break;
        }
    }
    console.log(isPrime ? "Yes" : "No");
});