Digit Manipulation

//Sum of Digits

int value = 12345;
         int res = 0;
         while ( value > 0){
            res = res + ( value % 10);
            value = value / 10;
        }
        System.out.println(res);

//Reverse a digit

int value = 12345;
        int res = 0;
        int rem = 0;
        while ( value > 0){
             res = (value %10);
             rem = rem *10 + res;
             value = value/10;    
         }
        System.out.println(rem);

//Multiplying all didgits

 int value = 2546987;
        int res = 1;
        while (value > 0){
            res = res *(value %10);
            value = value/10;
        }
        System.out.println("The Multiplication of Digits is"+ res);

// Max of all didgits

int value = 67854095;
       int max = value % 10;
       while( value > 0){
        int lastdigit = value %10;
        if ( max < lastdigit){
            max = lastdigit;
        }
        value = value /10;
       }
       System.out.println("The largest digit " + max); 

Armstrong Number - finding if the number is a armstrong number by using manual multiplication for finding the power

int num = 1634;
int aNum = 0;
int bcup = num;

while (num > 0) {
    int ld = num % 10;
    aNum += (ld * ld * ld * ld);
    num = num / 10;
}

if (bcup == aNum) {
    System.out.println("Is an Armstrong Number");
} else {
    System.out.println("Is NOT an Armstrong Number");
}

to find power of a number

int number = 10;
        int power = 4;
        int res = 1;
        for ( int i = 1 ; i <= power ; i++){
            res *= num
        }
        System.out.println("Power of give number is " + res);

Armstrong Number using a loop to find the power of number

int num = 1634;
            int aNum = 0;
            int bcup = num;
            int count = 0;
            while ( num > 0){    
                count++;
                num /= 10;
            }
            num = bcup;
            while ( num > 0){
                int ld = num %10;
                int pow = 1;
                for ( int i = 0; i < count ; i++){
                    pow = pow * ld;
                }
                aNum = aNum + pow;
                num /= 10;
            }
            if ( aNum == bcup){
                System.out.println("Is a Armstrong Number");
            } else {
                System.out.println("Is NOT a Armstrong Number");
            }