For the love of numbers

If I'm ever going to address this topic, today is a good day to do it. It's 7-8-9 day.

I like numbers. Sure, lots of people like to notice when their car odometer reaches 20000. But do they look forward to 20002? Or 21012? Or 23581.3? I like noticing patterns in numbers.

Examples:

• There are two towns on the highway between Rochester and my hometown or Decorah, IA that have the same population total (Town A's population = Town B's population.) That's cool. And that population total is palindromic -- it reads the same forward as back. That's even cooler.
  
• My friend John and I used to go to lunch at 11:23:58. Why? Because of the Fibonacci sequence: 1, 1, 2, 3, 5, 8 (the sum of two adjacent numbers gives you the next number in the sequence.)
• I had a special (surprise) celebration for Sherry when I had known her for exactly as many days in my life as I had lived before I knew her.
• And, so, since I know that the European way of indicating dates is YEar/MOnth/DAy, and since that makes the most sense to me for purposes of sorting things, I'm aware that today is 07/08/09. Which is cool. Of course, since I live in the good ol' USofA, I can also think it's cool again in just under two years. (699 days hence, if you care.)
• My earliest recollection of loving numbers and patterns in them was when I was entering 7th grade and I figured out that the digits of any number which has digits which sum to a number divisible by nine is always divisible by nine. The digits of 54, add to 9, (5+4=9) so 54 is 9*(some integer, in this case 6). And, since the digits of 13545261 add to 27, and 27 is divisible by 9, I know without checking that 13545261 is also divisible by 9.

Sure, I'm no Rainman. And I usually don't bring up my fascination around mixed company. But among other numerophiles, I get a kick out of sharing trivia like this.

Part of what makes numbers cool for me is number theory, which is one of those great mathematics branches that seems to have no use other than in making up puzzles, but is in fact quite cool and useful. I remember enjoying it quite a bit back in college.

So, if you are a lover of numbers, read this link which has a cool number trick at the top of the article. If you want to understand how it works, I'm afraid you'll need some number theory.