#include<bits/stdc++.h>
using namespace std;
using ll=long long;
ll a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,ans,tmp,hoge,fuga,piyo,sum;
ll A[200100],B[200100],C[200100],D[200100];
string st,str;
char ch;

vector<pair<long long, long long> > prime_factorize(long long N) {
    vector<pair<long long, long long> > res;
    for (long long a = 2; a * a <= N; ++a) {
        if (N % a != 0) continue;
        long long ex = 0;
        while (N % a == 0) {
            ++ex;
            N /= a;
        }
        res.push_back({a, ex});
    }
    if (N != 1) res.push_back({N, 1});
    return res;
}

int main(){
  cin>>n;
  if(n<=100000){
    m=1;
  }else if(n<=200000){
    ans+=60838190672;
    m=100001;
  }else if(n<=300000){
    ans+=257212470774;
    m=200001;
  }else if(n<=400000){
    ans+=596981215450;
    m=300001;
  }else if(n<=500000){
    ans+=1084296609104;
    m=400001;
  }else if(n<=600000){
    ans+=1722125036282;
    m=500001;
  }else if(n<=700000){
    ans+=2512661322551;
    m=600001;
  }else if(n<=800000){
    ans+=3457770622390;
    m=700001;
  }else if(n<=900000){
    ans+=4558987534475;
    m=800001;
  }else if(n<=1000000){
    ans+=5817729717828;
    m=900001;
  }else if(n<=1100000){
    ans+=7235062807366;
    m=1000001;
  }else if(n<=1200000){
    ans+=8812039622862;
    m=1100001;
  }else if(n<=1300000){
    ans+=10549659220862;
    m=1200001;
  }else if(n<=1400000){
    ans+=12448845177256;
    m=1300001;
  }else if(n<=1500000){
    ans+=14510332007222;
    m=1400001;
  }else if(n<=1600000){
    ans+=16734924755096;
    m=1500001;
  }else if(n<=1700000){
    ans+=19123138141378;
    m=1600001;
  }else if(n<=1800000){
    ans+=21675833225770;
    m=1700001;
  }else if(n<=1900000){
    ans+=24393634293809;
    m=1800001;
  }else if(n<=2000000){
    ans+=27276821356759;
    m=1900001;
  }else if(n<=2100000){
    ans+=30326413365285;
    m=2000001;
  }else if(n<=2200000){
    ans+=33542358268005;
    m=2100001;
  }else if(n<=2300000){
    ans+=36925459066686;
    m=2200001;
  }else if(n<=2400000){
    ans+=40476248899052;
    m=2300001;
  }else if(n<=2500000){
    ans+=44194833598353;
    m=2400001;
  }else if(n<=2600000){
    ans+=48081994935671;
    m=2500001;
  }else if(n<=2700000){
    ans+=52138123487538;
    m=2600001;
  }else if(n<=2800000){
    ans+=56363615930452;
    m=2700001;
  }else if(n<=2900000){
    ans+=60758384185743;
    m=2800001;
  }else if(n<=3000000){
    ans+=65323182791149;
    m=2900001;
  }else if(n<=3100000){
    ans+=70058785460280;
    m=3000001;
  }else if(n<=3200000){
    ans+=74964555109988;
    m=3100001;
  }else if(n<=3300000){
    ans+=80041527790312;
    m=3200001;
  }else if(n<=3400000){
    ans+=85290161753688;
    m=3300001;
  }else if(n<=3500000){
    ans+=90709780843282;
    m=3400001;
  }else if(n<=3600000){
    ans+=96301520878991;
    m=3500001;
  }else if(n<=3700000){
    ans+=102065855149715;
    m=3600001;
  }else if(n<=3800000){
    ans+=108002269398516;
    m=3700001;
  }else if(n<=3900000){
    ans+=114111807921375;
    m=3800001;
  }else if(n<=4000000){
    ans+=120394329084663;
    m=3900001;
  }else if(n<=4100000){
    ans+=126850549017804;
    m=4000001;
  }else if(n<=4200000){
    ans+=133479467089246;
    m=4100001;
  }else if(n<=4300000){
    ans+=140282617787827;
    m=4200001;
  }else if(n<=4400000){
    ans+=147259491582477;
    m=4300001;
  }else if(n<=4500000){
    ans+=154411235469265;
    m=4400001;
  }else if(n<=4600000){
    ans+=161737467121483;
    m=4500001;
  }else if(n<=4700000){
    ans+=169238102781982;
    m=4600001;
  }else if(n<=4800000){
    ans+=176913242475822;
    m=4700001;
  }else if(n<=4900000){
    ans+=184764302482181;
    m=4800001;
  }else if(n<=5000000){
    ans+=192790925674795;
    m=4900001;
  }else if(n<=5100000){
    ans+=200992441246692;
    m=5000001;
  }else if(n<=5200000){
    ans+= 209370037656611;
    m=5100001;
  }else if(n<=5300000){
    ans+=217923890158764;
    m=5200001;
  }else if(n<=5400000){
    ans+= 226653316365413;
    m=5300001;
  }else if(n<=5500000){
    ans+= 235560022983960;
    m=5400001;
  }else if(n<=5600000){
    ans+= 244642548171917;
    m=5500001;
  }else if(n<=5700000){
    ans+=253902107151677;
    m=5600001;
  }else if(n<=5800000){
    ans+= 263338334303632;
    m=5700001;
  }else if(n<=5900000){
    ans+= 272951354222680;
    m=5800001;
  }else if(n<=6000000){
    ans+= 282742772106696;
    m=5900001;
  }else if(n<=6100000){
    ans+=292711324081941;
    m=6000001;
  }else if(n<=6200000){
    ans+=302856699362737;
    m=6100001;
  }else if(n<=6300000){
    ans+=313180253381239;
    m=6200001;
  }else if(n<=6400000){
    ans+=323682486495499;
    m=6300001;
  }else if(n<=6500000){
    ans+=334361760892115;
    m=6400001;
  }else if(n<=6600000){
    ans+=345219904513529;
    m=6500001;
  }else if(n<=6700000){
    ans+= 356256480873339;
    m=6600001;
  }else if(n<=6800000){
    ans+= 367470747430202;
    m=6700001;
  }else if(n<=6900000){
    ans+=378864539458650;
    m=6800001;
  }else if(n<=7000000){
    ans+=390437889429971;
    m=6900001;
  }else if(n<=7100000){
    ans+=402188826344049;
    m=7000001;
  }else if(n<=7200000){
    ans+=414118956306590;
    m=7100001;
  }else if(n<=7300000){
    ans+=426229374669116;
    m=7200001;
  }else if(n<=7400000){
    ans+=438519040875971;
    m=7300001;
  }else if(n<=7500000){
    ans+=450987322450746;
    m=7400001;
  }else if(n<=7600000){
    ans+=463635895079489;
    m=7500001;
  }else if(n<=7700000){
    ans+=476465015795706;
    m=7600001;
  }else if(n<=7800000){
    ans+=489473701762655;
    m=7700001;
  }else if(n<=7900000){
    ans+=502662434241804;
    m=7800001;
  }else if(n<=8000000){
    ans+=516031076204871;
    m=7900001;
  }else if(n<=8100000){
    ans+=529581632274134;
    m=8000001;
  }else if(n<=8200000){
    ans+=543311223215741;
    m=8100001;
  }else if(n<=8300000){
    ans+=557220889209512;
    m=8200001;
  }else if(n<=8400000){
    ans+=571311613610574;
    m=8300001;
  }else if(n<=8500000){
    ans+=585584064718129;
    m=8400001;
  }else if(n<=8600000){
    ans+=600036645526326;
    m=8500001;
  }else if(n<=8700000){
    ans+=614670553358276;
    m=8600001;
  }else if(n<=8800000){
    ans+= 629486032479553;
    m=8700001;
  }else if(n<=8900000){
    ans+= 644482906053419;
    m=8800001;
  }else if(n<=9000000){
    ans+=659661281999214;
    m=8900001;
  }else if(n<=9100000){
    ans+=675021515919670;
    m=9000001;
  }else if(n<=9200000){
    ans+= 690561394962114;
    m=9100001;
  }else if(n<=9300000){
    ans+=706285619557381;
    m=9200001;
  }else if(n<=9400000){
    ans+=722190402701363;
    m=9300001;
  }else if(n<=9500000){
    ans+= 738276491989247;
    m=9400001;
  }else if(n<=9600000){
    ans+= 754546104527913;
    m=9500001;
  }else if(n<=9700000){
    ans+= 770997444637057;
    m=9600001;
  }else if(n<=9800000){
    ans+=787630213195247;
    m=9700001;
  }else if(n<=9900000){
    ans+=804447590347769;
    m=9800001;
  }else{
    ans+=821446543739323;
    m=9900001;
  }
  for(int i=m;i<=n;i++){
      const auto &pf = prime_factorize(i);
      long long res = 1;
      for (auto p : pf) res *= p.second + 1;
      ans+=i*res;
    }
  cout<<ans;
  return 0;
}

Measured memory_bytes: 3608