# Engineering professor finds 2017 Pearl Harbor anniversary day "mathematically special"

**PORTLAND, Ore. - **
Pearl Harbor's anniversary day this year is mathematically special. That's what Aziz Inan says. He's a professor of electrical engineering at the Donald P. Shiley School of Engineering at the University of Portland in Oregon.

Here's how he does the math for December 7, 2017. He says he's using the numbers from Wikipedia (https://en.wikipedia.org/wiki/Attack_on_Pearl_Harbor).

*On Sunday morning, December 7, 1941, the U.S. naval base Pearl Harbor in Hawaii was attacked by 353 imperial Japanese aircraft damaging nearly 20 American naval vessels including eight U.S. Navy battleships, with four sunk. One hundred eighty-eight U.S. aircrafts were destroyed; 2,403 Americans were killed and 1,178 others were wounded. The surprise attack came as a profound shock to the American people and led directly to America entering the Second World War.*

"As I hovered on the 76th anniversary date, I observed that this date possesses some interesting mathematical properties. For this reason, I decided to share these properties in this article in memory of those killed or injured in Pearl Harbor," writes Inan. He continues:

"If the 76th anniversary date of the Pearl Harbor attack expressed as 12/07/2017 is split in the middle into 1207 and 2017 respectively, these two numbers are made of the same digits 0, 1, 2, and 7, in different orders.

December 7 represented as 1207 equals 17 times the reverse of 17, namely 71. Note that 71 is the 20th prime number and 20 and 17 put side by side yields 2017, the 76th anniversary year.

Additionally, 2017 is the 306th prime number where 306 equals 17 times 18 (one more than 17).

The anniversary number 76 equals the sum of 17 and the 17th prime number, namely 59. Also, the prime factors of 76, namely 2 and 19, differ by 17.

Furthermore, the sum of the squares of the digits of 76 equals 5 times 17.

Moreover, 5 and 17 are the 3rd and 7th prime numbers where 3 and 7 put side by side equals 37, which is the sum of the leftmost and rightmost halves of 2017.

Also, the product of 3 and 7 multiplied by the reverse of 17, namely 71, gives 1491 and the reverse of 1491 is 1941, the year the Pearl Harbor attack took place.

Additionally, 3 times 7 equals the sum of 2 and 19, the prime factors of 76.

Also, the sum of the digits of 1941 equals 15 where the reverse of 15, namely 51, equals three times 17.

Lastly, 1941 equals 3 times 647 where the difference of these prime numbers can be expressed as 2 x 23 x 7 x 2, where 2, 23, 7, and 2 are the 1st, 9th, 4th, and 1st prime numbers, where 1, 9, 4, and 1 put side by side yield back 1941.

Aziz Inan can be reached at ainan@up.edu.