Java Program to Convert Decimal to Binary

public class DecimalToBinary {
    public static void main(String[] args) {
        int num = 19;
        long binary = convertDecimalToBinary(num);
        System.out.println(num + " in decimal = " + binary + " in binary.");
    }

    public static long convertDecimalToBinary(int n) {
        long binaryNumber = 0;
        int remainder, i = 1, step = 1;

        while (n != 0) {
            remainder = n % 2;
            n /= 2;
            binaryNumber += remainder * i;
            i *= 10;
        }

        return binaryNumber;
    }
}

19 in decimal = 10011 in binary.