Palindrome checker

What is a Palindrome?: A palindrome is a word, phrase, number, or other sequence of characters that reads the same forward and backward (ignoring spaces, punctuation, and capitalization). Examples include words like radar, level, and phrases like A man, a plan, a canal, Panama!
Word Palindromes: These are single words that are palindromic. Examples include deified, civic, and madam.
Phrase Palindromes: These are entire phrases that read the same way backward and forward. An example is Never odd or even.
Number Palindromes: These are numbers that read the same way backward and forward. Examples include 121, 12321, and 45654.
Examples of Palindromes: Madam

Racecar

Was it a car or a cat I saw?

12321