First, do you know what palindromes are? Palindromes are numbers that are the exact same when read from right to left or left to right. For example, 1001 is a palindrome since it reads 1001 from right to left and it also reads 1001 from left to right.
Another hint: Think about how many digits those numbers from 1000 - 100000 have. Could you possibly think of a way to use that?