C program to check perfect number; Through this tutorial, we will learn how to check perfect number in c program using for loop, while loop and function.

## C Program to Check Perfect Number

- C Program to find Perfect Number using For Loop
- C Program to find Perfect Number using While Loop
- C Program to find Perfect Number using Function

### C Program to find Perfect Number using For Loop

```
/* C Program to find Perfect Number using For Loop */
# include <stdio.h>
int main()
{
int i, Number, Sum = 0 ;
printf("\n Please Enter any number :- ") ;
scanf("%d", &Number) ;
for(i = 1 ; i < Number ; i++)
{
if(Number % i == 0)
Sum = Sum + i ;
}
if (Sum == Number)
printf("\n %d is a Perfect Number", Number) ;
else
printf("\n%d is not the Perfect Number", Number) ;
return 0 ;
}
```

**The output of the above c program; as follows:**

Please Enter any number :- 15 15 is not the Perfect Number

### C Program to find Perfect Number using While Loop

```
/* C Program to find Perfect Number using While Loop */
# include <stdio.h>
int main()
{
int i = 1, Number, Sum = 0 ;
printf("\n Please Enter any number :- ") ;
scanf("%d", &Number) ;
while( i < Number )
{
if(Number % i == 0)
Sum = Sum + i ;
i++;
}
if (Sum == Number)
printf("\n %d is a Perfect Number", Number) ;
else
printf("\n%d is not the Perfect Number", Number) ;
return 0 ;
}
```

**The output of the above c program; as follows:**

Please Enter any number :- 6 6 is a Perfect Number

### C Program to find Perfect Number using Function

```
/*C program to check nunber is perfect or not.*/
#include <stdio.h>
/*function to check perfect number or not*/
int isPerfect(int num)
{
int loop, sum = 0;
for (loop = 1; loop < num; loop++) {
if (num % loop == 0)
sum += loop;
}
if (sum == num)
return 1; /*Perfect Number*/
else
return 0; /*Not Perfect Number*/
}
int main()
{
int num, loop;
int sum;
printf("Enter an integer number: ");
scanf("%d", &num);
if (isPerfect(num))
printf("%d is a perfect number.", num);
else
printf("%d is not a perfect number.", num);
return 0;
}
```

**The output of the above c program; as follows:**

Enter an integer number: 9 9 is not a perfect number.