01 #include<stdio.h>
02 
03 int main()
04 {
05  int n,i=1,sum=0;
06  
07   printf("Enter a number:");
08   scanf("%d",&n); 
09   while(i<n)
10   { 
11    if(n%i==0)
12    sum=sum+i;
13    i++;
14   }
15   if(sum==n) 
16       printf("%d is a perfect number",i); 
17   else
18       printf("%d is not a perfect number",i); 
19       
20   return 0; 
21 } 

 OUTPUT :
 
 (1st Run )
 
 Enter a number : 6
 6 is a perfect number
 
 (2nd Run )
 
 Enter a number : 8
 8 is not a perfect number
 6