What's so special about the date 7-26-11?

What's so special about the date 7-26-11?

PORTLAND, Ore. - You may not have realized it but today's date is unique.

How so, you ask?

Well according to University of Portland Electrical Engineering Professor Aziz Inan, a math enthusiast who has a passion for numbers and dates, the date is extremely rare because it equals the product of three consecutive prime numbers (7262011 = 191 x 193 x 197).

According to Inan, this only happens every so often in history. The next date that is the product of three consecutive prime numbers is Dec. 11, 2039 and then after that we won't see it happen again until the year 3121.

Inan has compiled a list of all of the dates that are the product of three consecutive prime numbers, as well as a list of those that equal the product of two consecutive prime numbers.

And for those who are extra interested in this stuff (and can follow along), Inan sent us an email with some more fun facts. "There are other single full date numbers (still a very seldom occurrence) which equals the product of two, four, or more consecutive prime numbers," he wrote. Here's the math he sent us:

  • For example, in this century, September 27, 2009 expressed as 9272009 = 3041 x 3049!
  • Similarly, May 2, 2077 written as 5022077 = 2239 x 2243 and February 6, 2087 written as 2062087 = 1433 x 1439!
  • Also, March 7, 2091 expressed as 372091 = 607 x 613!
  • Note that some of these dates can also be interpreted in the day/month/year date format. Also, in the day/month/year date format, the full date number of 19 March 2019 written as 1932019 = 1381 x 1399!
  • Also, in last (20th) century, March 22, 1989 written as 3221989 = 1789 x 1801 and April 7, 1953 (or 4 July 1953 in day/month/year date format) expressed as 471953 = 683 x 691!
  • Also, 381923 = 617 x 619! Also, next (22nd) century, 412163 (which is April Fool’s Day in 2163!) = 641 x 643!