Happy 11-11-11, everyone!

Aziz Inan, professor of electrical engineering at the University of Portland, has given the numerical significance of Friday, Nov. 11, 2011 (11-11-11). Inan has turned the consideration of palindrome dates into a sort of hobby, and earlier this month proved himself a master of detecting numerical patterns when he dazzled us with facts about Wednesday, Nov. 2, 2011 -- a very rare 8 digit palindrome date (11022011). And this time he's back with some interesting revelations about 11-11-11.

Inan explains in an email, that 11-11-11 is a once-in-a-century repunit palindrome day. If you've never heard of the word "repunit" (our word-processing program had not), it means a number such as 11, 111, or 1111 that contains only the digit 1. Furthermore, he explains that 111111 equals the product of two palindrome numbers written as 111111=111 x 1001.

He points out that, this year, the month of November has been rich with palindrome days including 1-1-11 (another repunit day), 11-2-11, 11-3-11, 11-4-11, 11-5-11, 11-6-11, 11-7-11, 11-8-11, 11-9-11 and coming soon -- 11-22-11. Among them, 112211 is interesting because it equals 101 x 11 x 101, a palindrome expression.

Although you may have already surmised that after this Friday, the next time 11-11-11 will occur is 100 years from now in 2111, you have perhaps not considered -- as Inan has -- that, "interestingly enough, in 2111, 11-11-11 and eight-digit palindrome day 11-12-2111 will be two concurrent palindrome days!"

Once again Happy 11-11-11!