(I found this old post in my drafts, I guess I never clicked “publish”)
I already tweeted this site, but the more I thought about how beautiful and fun it makes numbers, I wanted to share some more.
Number Gossip is simple, and elegant, and makes it purpose clear:
Enter a number and I’ll tell you everything you wanted to know about it but were afraid to ask.
So since 42 is pretty obvious, I aimed at something more obscure… 41 or http://numbergossip.com/41 (Also I love sites that make URLs like this- you can build apps or link activities pretty easily into it).
So what’s the gossip about 41?
- 41 is the smallest non-palindromic prime which on subtracting its reverse gives a perfect cube (i.e., 41 – 14 = 33)
- 41 is the smallest half-quartan prime: p = (x4 + y4)/2
- 41 is the smallest number such that the sum of its divisors equals 3 times its reverse (41 + 1 = 3*14)
Wow, am I going to sound smart now… “non-palindromic prime”, wooot.
And the results beg for digging deeper- I learned what “odious” and “deficient” numbers are.
There is also a great set of links that will make any math teacher’s toes tingle.. maybe
If I was a math teacher, I would be all over this site. It’s great!
Confession: I learned abut this in a dead tree version of Wired.
I deplore the absence of “106” in this post. Which is an Ulam number AND an Evil number, dontchaknow?
That was an exercise left for the student. Excellent work, young man, your marks shall reflect your earnestness