#include<bits/stdc++.h>
#define ll long long
#define ld long double
#define int long long
using namespace std;
const ld eps=1e-10;
const int N=5e5+3;
const ll mod=998244353;
template<typename T>void read(T &x)
{
    x=0;char ch=getchar();ll f=1;
    while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
    while(isdigit(ch)){x=(x<<1)+(x<<3)+(ch^48);ch=getchar();}x*=f;
}
ll inv(ll i)
{
    if(i==1)return 1;
    return (mod-mod/i)*inv(mod%i)%mod;
}
int inv6=inv(6);
bool isprime[N];
int p[N+5],pos;
int p1[N+5]={0},p2[N+5]={0};
void prep(){
    isprime[0]=isprime[1]=1;
    for(int i=2;i<=N;i++)
        if(!isprime[i]){
            p[++pos]=i;
            for(int j=i*2;j<=N;j+=i) isprime[j]=1;
        }
    for(int i=1;i<=pos;i++){
        p1[i]=(p[i]+p1[i-1])%mod;
        p2[i]=(p2[i-1]+p[i]*p[i])%mod;
    }
}
ll n=0;
int tot=0;
ll R[N*2],g1[N*2],g2[N*2];
int id[N*2];
int where(ll x){
    if(x<=N) return id[x];
    else return id[N+n/x];
}

void solve() {
    prep();
    read(n);
    for(ll l=1,r;l<=n;l=r+1){
        r=n/(n/l);
        R[++tot]=r;
        if(r<=N) id[r]=tot;
        else id[n/r+N]=tot;
    }
    for(int i=1;i<=tot;i++){
        g1[i]=(R[i]*(R[i]+1)/2%mod-1+mod)%mod;
        g2[i]=(R[i]*(R[i]+1)%mod*(2*R[i]+1)%mod*inv6%mod-1+mod)%mod;
    }
    for(int i=1;i<=pos&&p[i]*p[i]<=n;i++){
        for(int j=tot;R[j]>=p[i]*p[i];j--){
            int k=where(R[j]/p[i]);
            g1[j]=(g1[j]-(p[i])*(g1[k]-p1[i-1]+mod)%mod+mod)%mod;
            g2[j]=(g2[j]-(p[i]*p[i]%mod)*(g2[k]-p2[i-1]+mod)%mod+mod)%mod;
        }
    }
    int cnt1=(g1[tot]-g1[tot-1]+mod)%mod;
    int cnt2=(g2[tot]-g2[tot-1]+mod)%mod;
    int ans=(n*(n+1)/2%mod+mod-1-cnt1)%mod;
    ans=ans*ans%mod;
    ans=(ans-(n*(n+1)%mod*(2*n+1)%mod*inv6%mod)+mod+1+cnt2)%mod*(mod+1)/2%mod;
    printf("%lld\n",ans);
}
signed main()
{
    int T=1;
    //read(T);
    while(T--)solve();
    return 0;
}