and with a UCLA connection. The number is 2^{43,112,609}-1, it has 13,000,000 digits, and it wins for the Great Internet Mersenne Prime Search and the UCLA Math Department "a $100,000 prize from the Electronic Frontier Foundation for being the first to find a prime number that has more than 10 million digits."

"More prizes remain to be claimed: a $150,000 award for a prime with 100 million digits, and a $250,000 award for one with a billion digits." And remember the good news: As even some people from 2000 years ago could tell you, there's sure to be an even larger number somewhere between this one and its factorial plus 1. So get going, folks! (Well, OK, even between this one and twice this one, but that's harder to prove.)

Thanks to my UCLA undergraduate classmate and now computer science professor Haym Hirsh for the pointer.