C Program to Check a Number is Perfect or Not

Program :-

#include <stdio.h>
main(){
    int i, num ,sum = 0;
    printf("enter the number : ");
    scanf("%d",&num);
    for(i = 1 ; i <= num /2 ; i++)
    {
        if(n % i == 0){
            sum = sum + i;
        }
     }
     if ( sum == num)
         printf("\n number is perfect");
     else
         printf("\n number is not perfect");
 }

Output:-

enter the number
6
number is perfect

Algorithm to Check a Number is Perfect or Not

Step 1 : Start

Step 2 : Read Number

Step 3 :  i = 1 ,Sum = 0

Step 4 : if  i <= Number / 2 then go to Step 5  
             else go to Step 8
Step 5 : if  Number % i = 0 then go to Step 6
             else go to Step 7
Step 6 : Sum = Sum + i
Step 7 : i = i + 1 , then  go to Step 4
Step 8 : if  Sum = Number then go to Step 9
             else go to Step 10
Step 9 : print "Number is Perfect" ,go to Step 11
Step 10 : print "Number is not Perfect" ,go to Step 11
Step 11 : Stop