Check wheather a number is Perfect number or not.
Perfect number are summation of divisors of a number exclude the number ownself.
Eample 6,28.
Lets check 28. From 1 to 27 we need to check which number can divide 28.
then sum of all those number whose are divisors of 28.
28 = 1,2,7,14(divisors).
Now make sum of all divisors
1+2+7+14 = 28
so 28 is perfect number.
Again 6 divisors are 1,2,3
so, 1+2+3 = 6 which is also perfect number.
C program:
#include <stdio.h>
int main()
{
int number,perfect_number,start=1,sum=0;
printf("Input Any Number: \n");
scanf("%d",&number);
while(start<number)
{
if(number%start == 0)
sum= sum+start;
start ++;
}
if(sum ==number)
{
printf("%d is perfect number\n",number);
}
else
{
printf("%d is not perfect number\n",number);
}
return 0;
}