As said:

One caveat: The reversed number might be much larger than the original number (e.g. 123456789 becomes 987654321). It is possible that the original number is below MAX_SAFE_INTEGER, but the reversed number isn't. Rounding errors will lead to a wrong result in that case (it could be considered an edge case however, and could be resolved by limiting the maximum integer further than MAX_SAFE_INTEGER).

Please at least document this limitation.