Five of them.
There are 90 four-digit palindromes
There is 90 four digit palindromes.
There are no four-digit perfect squares that are palindromes.
There are 900 6-digit palindromes.
There are 10 3-digit odd palindromes that are divisible by five.
90 of them.
9 of them.
For there to be palindromes, each digit must be replicated. Therefore there are at most three distinct digits.If there are 3 pairs of different digits, then there are 6 palindromes. If there can be more duplicate digits, then there are 27 palindromes.