Palindromes are achiral words, such as:

• nun
• madam
• pop

Or achiral phrases (once spaces and punctuation are removed, by convention) such as these famous examples:

• Nurses, run!
• Madam, I'm Adam!
• A man, a plan, a canal: Panama!

Or achiral sequences, such as a palindromic gene segment:

• GATTATATTAG

Or numbers:

• 123454321

Try this one out...

• 11 x 11 = 121
• 111 x 111 = 12321
• 1,111 x 1,111 = 1234321
• 111,111,111 x 111,111,111=12345678987654321

(...what happens when we get past a nine digit number?)

This is not a palindrome:

((()))

But this is:

((((((

And this is:

(())((

Which makes me:

:( non (:

Palindrome Adjacent Concepts: the Ambigram

How about words which - font-willing - appear the same reflected in a mirror placed beside them Eg -

• bod
• dob

Here they need “mirror symmetry” about a vertical line through their center.

Or words which appear the same when reflected in a mirror placed above them -

• coco

For that they need “mirror symmetry” about a horizontal line through their center.

how about words which appear the same when rotated, by “turning” the page upside (no mirrors this time), for example:

• NOON

External references

• Numeric Palindromes
• ambigram - wikipedia