Perfect Numbers

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    */
 
    // Determine whether the given number is a perfect number.
    function isPerfect($number)
    {
        // Only positive integers can be perfect.
        if ($number < 1)
        {
            return false;
        }
 
        // Calculate the factors for the given number.
        for($i = 1; $i <= $number; $i++)
        {
            if ($number % $i == 0)
            {
                $arrFactors[] = $i;
            }
        }
 
        // A perfect number is a number that is half the sum of all of its positive divisors (including itself).
        return ($number == array_sum($arrFactors) / 2) ? true : false;
    }
?>