A palindrome is a number or a word that reads the same backwards and forwards. "121" in a palindrome but "122" is not. "1223221" is a palindrome but ""12223221" is not.
There's a kinda cool, kinda disturbingly long list here, and I'm sure that you can search for other lists if you're interested.
Type in a number here: and we'll tell you if it's a palindrome or not.
Output: