2^74,207,281-1

[sanctus]

The title says it all, I am just amazed by it.

 

I mean I know there is a theorem stating that there is an infinity of them implying no biggest one, but 22million digits....

[CraigD]

That's a big Mersenne prime! I’m mathic enough to recognize that’s likely what it was, but googled up its GIMPS press release to be sure.

 

It makes me feel dated to realize that some of my earliest computers didn’t have enough memory or even storage to even represent this number (a bit less than 9 MB). Now, my browser uses 200 MB just rendering all the pretty graphics for the webpages talking about it

 

It’s cool that the giant prime hunters involved in this discovered a bug in Intel’s high-end Skylake CPU – give’s people who like to do this sort of thing a response to people who say they’re just wasting energy and hardware.

 

I only vaguely understand how you prove that a number like this is prime - a good opportunity to brush up on my math!

[sanctus]

CraigD I love this part of the GIMPS-release link you posted:

The official discovery date is the day a human took note of the result. This is in keeping with tradition as M4253 is considered never to have been the largest known prime number because Hurwitz in 1961 read his computer printout backwards and saw M4423 was prime seconds before seeing that M4253 was also prime.