#include <iostream>
#include <random>
using namespace std;

using int64 = long long;

namespace Random
{
    static random_device rnd;
    static mt19937_64 mt(rnd());

    // n未満の非負整数をランダムに返す
    int64 randInt(int64 n)
    {
        return mt() % n;
    }

    // [a, b)に属する整数をランダムに返す
    int64 randInt(int64 a, int64 b)
    {
        int64 width = b - a;
        return randInt(width) + a;
    }
};

namespace Mod
{
    const int64 MOD = 1e9 + 7;

    int64 powMod(int64 a, int64 n, int64 mod = MOD)
    {
        int64 res = 1, p = a;
        while (n > 0)
        {
            if (n & 1) res = (res * p) % mod;
            p = (p * p) % mod;
            n >>= 1;
        }
        return res;
    }
};

namespace Prime
{
    enum Result { PROBABLY_PRIME, COMPOSITE };

    // 時間計算量:O(klog^3 n)
    // nが合成数なのに素数であるという判定をしてしまう確率はたかだか4^{-k}
    Result millerRabin(int64 n, int k)
    {
        if (n <= 1) return COMPOSITE;
        if (n == 2) return PROBABLY_PRIME;
        if (n % 2 == 0) return COMPOSITE;

        int64 s = 0, d = n - 1;
        while (d % 2 == 0) { s++; d >>= 1; }

        for (int i = 0; i < k; i++)
        {
            int64 a = Random::randInt(1, n);

            if (Mod::powMod(a, d, n) == 1) continue;
            bool all = true;
            for (int64 r = 0; r < s; r++)
            {
                if (Mod::powMod(a, (1LL << r) * d, n) == n - 1)
                {
                    all = false;
                    break;
                }
            }
            if (all) return COMPOSITE;
        }
        return PROBABLY_PRIME;
    }
};

int main()
{
    int N;
    cin >> N;

    if (Prime::millerRabin(N, 100) == Prime::PROBABLY_PRIME)
    {
        cout << "YES" << endl;
    }
    else
    {
        cout << "NO" << endl;
    }

    return 0;
}