# Perfect Number in C

By | October 4, 2021 Here in this program, we will write a code which checks whether the entered number is a Perfect number or not.

## What is a Perfect number?

When a positive integer is equal to the sum of its all possible divisors except itself, is known as a perfect number.

For example, 6 is a perfect number because the sum of its all divisors is equal to 6

Divisors of 6 are 1, 2, 3 exclude 6.

Sum of 6 all divisors = 1+2+3 = 6

### Statements to use:

• For loop
• If statements
• Else statement

Steps:

• First, we will ask the user to enter a positive integer
• Then we start a loop from 1 to the half of the entered number
• Inside the loop, we will check which number is the divisor of the entered number.
• If the number is a divisor of the entered number, we will sum it.
• At last, we will check whether the summing of all the divisors is equal to the entered number or not
• If it is equal to the entered number, we will print It is a perfect number, is not we will print it is not a perfect number.

### Perfect Number in C

```#include<stdio.h>
#include<conio.h>
void main()
{
int num, sum=0,i;
clrscr();
printf("Enter a Positive Integer: ");
scanf("%d",&num);
if (num==1)
{
printf("It is not a Perfect number");
}
else
{
for(i=1;i<=num/2;i++)
{
if(num%i==0)
sum+=i;
}
if(sum==num)
printf("It is a perfect number");
else
printf("It is not a perfect number");
}
getch();
}
```

Output:

Enter a Positive Integer: 6

It is a perfect number 