include <bits/stdc++.h>

using namespace std;
int main()
{
long long n,tong=0;
cin>>n;
for(long long i=1;i<=sqrt(n);i++)
if(n%i==0){
if(i==n/i)
tong=tong+i;
else
tong=tong+i+n/i;
}
if(tong/2==n)
cout<<"YES";
else
cout<<"NO";
return 0;
}