#include <cassert>
#include <iostream>
using namespace std;
constexpr int mod = 998244353;

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

    assert(N <= 1e7);

    long long ret = 0;
    for (int d = 1; d <= N; ++d) {
        int k = (N + 1) / d;
        int md = (N + 1) % d;
        ret += (long long)d * ((k - 1) * k / 2 % mod) % mod + (long long)k * md % mod;
    }
    cout << ret % mod << '\n';
}