0ryant

    public static boolean isPerfectNumber(int number){
        if (number<1){
            return false;
        }
        int accum=0;
        for (int i=1; i<=(number/2);i++){
            if (number%i==0){
                accum+=i;
            }
        }

0ryant

    public static void printFactors(int number){
        if (number <1){
            System.out.println("Invalid Value");
        }
        String factors="";
        for (int i = 1;i<=number;i++){
            if(number%i==0){
                factors+=i+" ";
            }
        }

0ryant

    public static int getGreatestCommonDivisor(int first, int second){
        if ((first<10)||(second<10)){
            return -1;
        }
        int gtDivisor=1;
        for (int i=2;i<=((first+second)/2);i++)
            if ((first%i==0)&&(second%i==0)){
                gtDivisor=i;
        }
        return gtDivisor;

0ryant

   public static boolean hasSharedDigit(int num1, int num2) {

        if ((num1 < 10) || (num1 > 99) ||
                (num2 < 10) || (num2 > 99)) {
            return false;
        }
        
        for (int i = num1; i != 0; i /= 10) {
            for (int j = num2; j != 0; j /= 10) {
                if (i%10 == j%10) {

0ryant

    public static int getEvenDigitSum(int number){

        if (number < 0){
            return -1;
        }

        int sum=0;
        for (int i = number; i !=0; i /= 10){
            if ((i%10)%2==0){
                sum+=i%10;

0ryant

    public static int sumFirstAndLastDigit(int number){

        if (number < 0 ) {
            return -1;
        }

        int firstDigit = number%10;
        int lastDigit=0;
        for (int i = number; i != 0; i /= 10){
            lastDigit = i%10;

0ryant

public class NumberPalindrome {

     public static boolean isPalindrome(int number){

        if (number < 0){
            number = number - (number*2);
        }

        String reverseNumber = "";
        int newNumber = number;

0ryant

public class MinutesToYearsDaysCalculator {

    public static void printYearsAndDays(long minutes){

        if (minutes <0) {
            System.out.println("Invalid Value");
        } else {
            long years = minutes / 525600;
            long minutesRemaining = (minutes - (years * 525600));
            long daysRemaining = minutesRemaining / 1440;

0ryant

public class AreaCalculator {

    public static double area (double radius) {

        if (radius<0) {
            return -1.0d;
        }

        double areaOfCircle = ((Math.PI * (radius*radius)));
        return areaOfCircle;

0ryant

public class TeenNumberChecker {

    public static boolean hasTeen(int a,int b,int c){

        if (a >=13 && a <=19 ||
            b >=13 && b <=19 ||
            c >=13 && c <=19 ) {
            return true;
        }
        return false;