Perfect Number is a number which is equal to sum of it’s proper divisors.
Example 1: 6 has proper divisors 1,2,3. 1+2+3 = 6. Hence it is a Perfect Number.
Example 2: 10 has proper divisors 1,2,5. 1+2+5 != 6. Hence it is not a Perfect Number.
Java
import java.util.*;
public class PerfectNumber
{
public static void main(String args[])
{
int n=0,sum=0;
Scanner sc=new Scanner(System.in);
System.out.print("Enter a number: ");
n=sc.nextInt();
for(int i=1;i<n;i++)
{
if(n%i==0)
{
sum=sum+i;
}
}
if(sum==n)
{
System.out.println(n+" is a Perfect Number");
}
else
{
System.out.println(n+" is not a Perfect Number");
}
}
}