Cool Primes: 37 & 73 🙂
Our son Adam just turned 37 (yes, we’re old!). In honor of this event, lets look at a couple of cool properties of 37 and its ‘mirror image’ 73. They may seem like boring numbers (though how can any number – let alone a prime – be boring?! :-)), but they’re not . . . .
1. First for 37: It has this interesting divisibility property: It is the only two-digit* number the ‘goes into’ all 9 of 111, 222, 333, 444, 555, 666, 777, 888, and 999.
* There is ONE one-digit number (besides 1!) and ONE 3-digit number that also divide all nine of these, and with some thought, they should ‘easy’ to find.
2. As for 73: Some of you know that Sheldon on The Big Bang considers 73 to be the ‘best number’. Whether you’re a Big Bang fan or not, you might find his reasoning both interesting and hilarious. See the clip here: Sheldon & 73
A little extra lagniappe . . . Look at the two numbers 3773 and 7337. Neither of them is prime, but it turns out that they are both divisible by 11** (as well as several others.)
**I find this fascinating (am I the only one? 🙂 ): It turns out (and can be proven) that any four-digit palindromic number (some forwards as backwards) will be divisible by 11!