C Program to Check Perfect Number

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.

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