This Week Is Palindrome Week

"Tattarrattat" is the longest word in the Oxford English Dictionary. The word was coined by James Joyce in his 1922 book "Ulysses" to describe a knock on the door. Getty Images/Image Source

This week is palindrome week—every date reads the same forwards and backwards: 7/11/17, 7/12/17, 7/13/17, 7/14/17... you get the point.

Just like words and phrases can be palindromes—mom, racecar, level, live not on evil—so too can numbers.

The palindrome has a long history that goes all the way back to the ancient Greeks, who would inscribe palindromic phrases on fountains. One of the most popular fountain inscriptions was "wash the sin as well as the face." Although that phrase isn't a palindrome in English, it is one in Greek.

Check out how the week is being celebrated on social media below: