C++ Program to find Perfect Number

Perfect number is a positive number which sum of all positive divisors excluding that number.

For example: 6 is Perfect Number since divisor of 6 are 1, 2 and 3. Sum of its divisor is
1 + 2+ 3 =6
and 28 is also a Perfect Number
since 1+ 2 + 4 + 7 + 14= 28
Other perfect numbers: 496, 8128
Example:

#include<iostream> 
#include<cctype>
using namespace std; 

int main(){
    int n,i=1,sum=0;
    cout << "Enter a number: ";
    cin >> n;
       while(i<n){
       if(n%i==0)
       sum=sum+i;
       i++; 
}
 
if(sum==n)
    cout << i << " is a perfect number\n"; 
else
    cout << i << " is not a perfect number\n";
    system("pause"); 

return 0;

}

Program Output:

6 is a perfect number

15 is not a perfect number
28 is a perfect number
496 is a perfect number