By Aziz Inan
Like anyone who was born in 1955, this year I will turn 55, a special age which coincides with the rightmost two digits of my birth year. I got so excited about this rare occurrence that I decided to explore my new age number further and, guess what, you will be fascinated with what I found out.
First, 55 equals the sum of all integers from 1 to 10, where 10 equals the sum of the digits of 55.
Second, 55 equals the sum of the squares of all integers from 1 to 5, where 5x5 is the product of the digits of 55.
Third, 55=15+40 where 15 equals the sum of all powers of 2 from 0 to 3 given by 15=1+2+4+8 and 40 is the sum of the powers of 3 from 0 to 3, that is, 40=1+3+9+27.
Fourth, 55 is a palindrome number since it reads the same forward or backward.
My last palindrome age occurred 11 years ago at age 44 and after this age, I have to wait another 11 years for my next palindrome age, 66.
Next, 55 is also a Fibonacci number. Fibonacci numbers consist of a simple series of numbers first introduced in a book titled "Liber Abaci" published in 1202 by Italian mathematician Leonardo Fibonacci (1170-1250).
This number series begins with numbers 0 and 1. After that, each number in the series is obtained by adding the previous two numbers of the series such as 0+1=1, 1+1=2, 1+2=3, 2+3=5, 3+5=8, 5+8=13, etc. which leads to 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, etc.
Note that my last Fibonacci age before I turn 55 occurred 21 years ago at age 34 and after this year, one more final Fibonacci age could possibly occur 34 years later in my lifetime at age 89. Interestingly enough, my new age 55 is the only Fibonacci number that is also a palindrome number.
I realized that 55 is also a Kaprekar number. A Kaprekar number, named after Indian mathematician Dattatreya Ramachandra Kaprekar (1905-1986), is a positive integer whose square split into two parts around the middle add up to the original number.
For example, 9 is a Kaprekar number since 9x9=81 and if 81 is split into 8 and 1, 8+1 yields back 9; 45 is also a Kaprekar number since 45x45=2025 and 20+25=45, etc.
The first few Kaprekar numbers are 1, 9, 45, 55, 99, 297, 703, etc. Note that the square of my new age is 55x55=3025 and 30+25 yields back 55.
My previous Kaprekar age occurred 10 years ago at 45 and after age 55, if I live long enough, I could experience one more Kaprekar age 44 years later when I turn 99.
I also discovered another connection between my birth year and my new age.
If 1955 is split in the middle into numbers 19 and 55, their product is 19x55=1045 where if 1045 is again split as 10 and 45, 10+45 yields my new age 55. The same is also true for the reverse of my birth year, that is, split number 5591 into 55 and 91, take their product as 55x91=5005 and guess what, 50+05=55!
I also discovered that my new age 55 corresponds to the atomic number of a chemical element called cesium, discovered in 1860 by German chemist Robert Bunsen (1811-1899) and German physicist Gustav Robert Kirchhoff (1824-1887) and interestingly enough, this year marks the 150th anniversary of this discovery.
When I turn 55, I have no doubt that I will pay more attention to the 55 m.p.h. speed limit signs on freeways. Also, I will pay more attention to time when it is 55 minutes passed every hour and especially in the evenings when it is 19:55.
Also, I will tell my students that I teach 55 minute long classes because of my new age. And I will continue to treasure my Fibonacci palindrome age while it lasts because I know this will never happen again.
Aziz Inan is a professor of