My code works for 200,000 prime numbers but shows segmentation error(core dumped) when i try to run it for 2,000,000 numbers

'My code works for 200,000 prime numbers but shows segmentation error(core dumped) when i try to run it for 2,000,000 numbers'

using namespace std;
int main(){
long long n;
cin>>n;
long long prime[n];
for(long long i=0;i<=n;i++){
    prime[i]=1;
}
prime[0]=0;
prime[1]=0;
for(long long i=2;i<=sqrt(n);i++){
for(long long j=2;i*j<=n;j++){
    prime[i*j]=0;
}
}
unsigned long long res=0;
for (long long i = 2; i <= n; ++i){
    if(prime[i]==1){
    res+=i;
    }
}
cout<<res;
}