Yesterday we reported on the impending announcement of two newly discovered mammoth prime numbers, and the details, now out, do not disappoint. According to the Great Internet Mersenne Prime Search (GIMPS), the volunteer-powered distributed-computing group responsible for finding most of the largest known primes (a prime number is divisible only by 1 and itself), both are larger than any other known primes: one clocks in at nearly 13 million digits in length and the other at a slightly smaller 11.2 million digits.

That’s good news for Edson Smith, a computing resource manager in the math department at the University of California, Los Angeles: It was his machine that stumbled upon the larger prime (243,112,609 - 1 in shorthand), so he's in to claim the $100,000 prize offered by the Electronic Frontier Foundation for the discoverer of the first 10-million-plus-digit prime. (The smaller of the new primes, turned up by a German GIMPS member, would also have qualified for the prize but was discovered two weeks later.) Under a prize-sharing agreement implemented by GIMPS, Smith or his institution would receive half the prize, with $25,000 going to charity, $5,000 going to GIMPS to cover expenses, and the balance going to past GIMPS volunteers who discovered lesser primes.

Reached at his office, Smith called the discovery “quite unexpected.” He says he installed the software needed to participate in GIMPS in the fall of 2007 in all 75 or so machines in his computer lab. “We thought it would be a good thing to use to get undergraduates interested in computational mathematics,” he says. (Little did he know that it would bring about the thing that gets undergraduates’ attention best—cash.) “It’s been sort of off my radar for quite some time, because frankly it’s such well-written software that it doesn’t need any maintenance. And in my business, you put something in, and if it doesn’t require any maintenance you just let it go.”

Asked if he was on pins and needles as the record-setting prime underwent verification on various other member computers around the world, Smith demurred. “I would like to tell you that," he says, "but school’s starting in less than two weeks for us, and this is the height of my busy season. In the time I’ve had to think about it, it’s been really exciting.”