A number is perfect if it is equal to the sum of its proper divisors (i.e., not counting itself). For example, 6 = 1 + 2 + 3 and 28 = 1 + 2 + 4 + 7 + 14 are the first two perfect numbers.

The following program prints all perfect numbers between 1 to 100.

// Mukesh Tekwani

class PerfectNumbers
{
	public static void main(String [] args)
	{
		int n; 	//number which is to be checked

		for(n = 1; n <= 100; n++)
		{
			if (isPerfectNum(n))
				System.out.println(n + " is a perfect number");
		}
	}

	static boolean isPerfectNum(int n)
	{
		int sum = 0, i;
	
		for(i = 1; i < n; i++)
		{
			if (n % i == 0)		
				sum = sum + i;
		}

		if (sum == n)
			return true;
		else
			return false;
	}
}