$\color{#1c1c1c}{\text{tu}}$$\color{#363636}{\text{a}}$$\color{#4f4f4f} {\text{n}}$$\color{#696969}{\text{d}}$$\color{#828282} {\text{u}}$$\color{#9c9c9c}{\text{n}}$$\color{#b5b5b5} {\text{m}}$$\color{#cfcfcf}{\text{a}}$$\color{#eee9e9}{\text{i}}$

#include<bits/stdc++.h>
using namespace std;

int main() {
   long long n,s=0;
   cin>>n;
   for(int i=1;1ll*i*i<=n;i++){
        if(n%i==0)
           s=s+i+n/i;
        if(i*i==n)
           s=s-1;
    }
    if(s/2==n)
        cout<<"YES";
    else
        cout<<"NO";
return 0;
}

`\color{blue}{team} \color{black}{manh} \color{blue}{đô} \color{black}{ng}`

`Python:`

def Check(n):
    if n <= 0:
        return "NO"
    s = 0
    for i in range(1, n + 1):
        if n % i == 0:
            s += i
    if s == 2 * n:
        return "YES"
    else:
        return "NO"
n = int(input())
print(Check(n))

`C++:`

#include <bits/stdc++.h>
#define int long long
using namespace std;
bool Check(int n)
{
  if (n <= 0) return false;
  int s = 0;
  for (int i = 1; i <= n; i++)
  {
    if (n % i == 0) s += i;
  }
  return s == 2 * n;
}
signed main()
{
  int n; cin >> n;
  if (Check(n)) cout << "YES";
  else cout << "NO";
}