Palindrome Number

Determine whether an integer is a palindrome. Do this without extra space.

Negative number is not palindrome, then compare reversed(int) == int.

public boolean isPalindrome(int x) {
        //negative number is not a palindrome
        if (x<0) {
            return false;
        }

        long number = x;
        long reverse = 0;

        while (number!=0) {
            long remainder = number%10;
            reverse = reverse * 10 + remainder;
            number = number / 10;
        }

        return x==reverse; 
    }