by R4R Team

Perfect number :
-The sum of all factors of number are equal to that number then number is known as perfect number.

Example-
6 is a perfect number.
Factors 1,2,3 and there sum is also 6

program-

#include< stdio.h>
int main() {
int i,n=0,sum=0;
printf("Enter Number\n");
scanf("%d",&n);
for(i=1;i< n-1;i++)
{
if(n%i==0)
sum=sum+i;
}
if(n==sum)
printf("Perfect number");
else
printf("Not Perfect number");

}

output-

Enter Number
6
Perfect number

Enter Number
28
Perfect number

Enter Number
5
Not Perfect number

-In this program, we take an input of the integer number and try to check it is perfect number or not.
-Firstly we find all factors of that number and add all factor.
-At last compare both number, if they are same then it is perfect number otherwise it's not.