A palindromic number is a number whose digits, with decimal representation usually assumed, are the same read backward, for example, 5885. They are studied in recreational mathematics where palindromic numbers with special properties are sought. A palindromic prime is a palindromic number that is a prime number, for example, 191 and 313.
A palindrome is a word, phrase, number, or other sequence of characters which reads the same backward as forward, such as madam or racecar. Sentence-length palindromes may be written when allowances are made for adjustments to capital letters, punctuation, and word dividers. Aqui ficam alguns exemplos: