This is a nice question to get warmed up. However, the question should specify that negative integers are not permitted. As written, it is undefined if -334433 is considered a valid palindrome or not, for example. On the number line, it is clearly a palindrome. As a string, it is not, due to the extra character in front, but this question is explictly about integers.
The choice to not allow negatives seems arbitrary so should be made specific.