  Everybody has certainly heard about palindromes: words that stay the same
when read backwards. For instance kayak, radar, or rotor. Mathematicians are
interested in palindromic numbers: positive integers whose expansion in a
certain integer base is a palindrome. The following problems are studied:
palindromic primes, palindromic squares and higher powers, multibased
palindromic numbers, etc. In this paper, we define and study antipalindromic
numbers: positive integers whose expansion in a certain integer base is an
antipalindrome. We present new results concerning divisibility and
antipalindromic primes, antipalindromic squares and higher powers, and
multibased antipalindromic numbers. We provide a user-friendly application for
all studied questions.
