cses_sum_of_divisors

#include <bits/stdc++.h>
using namespace std;
#define ll long long
const ll nmax=1e9+7;
ll int_sqrt (ll x) {
  ll ans = 0;
  for (ll k = 1LL << 30; k != 0; k /= 2) {
    if ((ans + k) * (ans + k) <= x) {
      ans += k;
    }
  }
  return ans;
}
int main()
{
    ll n;
    cin>>n;
    ll sq=int_sqrt(n);
    ll ans=0;
    for (ll i=1; i*i<=n; i++){
        ans+=((i*(n/i))%nmax+(((n/i)*(1+n/i))/2)%nmax)%nmax;
    }
    ans=(ans+nmax-(((((sq%nmax)*((sq+1)%nmax))/2)%nmax)*sq)%nmax)%nmax;
    cout<<ans<<"\n";
}