# C Program to Check Perfect Number

A perfect number is a positive integer number in which sum of all positive divisors excluding the number itself is equal to that number.

For example: 28 is perfect number since its divisors are 1, 2, 4, 7 and 14. Sum of divisors is: 1+2+4+7+14=28.

Other examples of perfect number are: 6, 496 etc.

## Perfect Number C Program

``````
#include<stdio.h>
#include<conio.h>
#include<math.h>

int main()
{
int number, sum=0, i;
clrscr();
printf("Enter number: ");
scanf("%d", &number);

/* Finding sum */
for(i=1; i< number; i++)
{
if(number%i==0)
{
sum = sum +i;
}
}
/* Making decision */
if(sum == number)
{
printf("%d is PERFECT.", number);
}
else
{
printf("%d is NOT PERFECT.", number);
}
getch();

return(0);
}
``````

Output of the above program :

```Run 1:
-------------
Enter number: 6 ↲
6 is PERFECT.

Run 2:
-------------
Enter number: 36 ↲
36 is NOT PERFECT.

Run 3:
-------------
Enter number: 496 ↲
496 is PERFECT.

Note: ↲ indicates enter is pressed.
```