Nice javadoc!

Thank you!

This looks great 😄

Thank you!

What changes would you have to make to get this working for negative numbers?

To support negative numbers, I would handle the sign separately.

The current loop only works for positive numbers because it runs while remainingNumber > 0. For a negative number, I would first check whether the original number is negative, then reverse the absolute value of the number, and finally return the result as negative again if needed.

I could update the method like this:

private static int reverseNumber(int number) {
    boolean isNegative = number < 0;
    int remainingNumber = Math.abs(number);
    int reversedNumber = 0;

    while (remainingNumber > 0) {
        int digit = remainingNumber % 10;
        reversedNumber = reversedNumber * 10 + digit;
        remainingNumber = remainingNumber / 10;
    }

    if (isNegative) {
        return -reversedNumber;
    }

    return reversedNumber;
}

For example, -3956 would return -6593.

Would this be a good way to handle negative numbers?

Yep nice one - this looks good to me!!