## Q. C Program to Check Whether the Given Number Is Perfect Number or Not.

Here you will find an algorithm and program in C programming language to check whether the given number is perfect number or not. First let us understand what Perfect number means.

Explanation : Perfect number is a positive integer equal to the sum of its proper divisors.

For Example : 6 is perfect number because sum of its proper divisor(1, 2, 3) is equal to 6.

## Perfect Number Algorithm

```START
Step 1 - Input the number.
Step 2 - Find all divisors of the number except the number itself.
Step 3 - If the sum of all divisors of the number is equal to the number, then return true. Else, return false.
STOP
```

# Perfect Number Program

```//C program to check whether the given number is Perfect Number or not
#include <stdio.h>
int main()
{
int num=28,i;
int sum;
sum=0;
for(i=1; i< num;i++)
{
if(num%i==0)
sum+=i;
}
if(sum==num)
printf("%d is a perfect number.",num);
else
printf("%d is not a perfect number.",num);
return 0;
}
```

#### Output

```28 is a perfect number.
```