"New Largest Prime Number Is 17 Million Digits Long"

From Time:

Curtis Cooper, a researcher at the University of Central Missouri, reportedly spent four years searching for the new prime number. And in late January, his quest was confirmed. Behold the new longest prime number in the world: 2^57,885,161 – 1.

The new discovery, at 17,425,170 digits, crushes the 2008 record number of 12,978,189 digits. Cooper is something of a legend when it comes to prime-number discovery: this is the third one found by him and his team.

The professor in charge was on Radio 4 this morning, the interviewer asked him what the practical application of the new prime number was and he chuckled and replied "None whatsoever. Maybe they'll find a use for it in a hundred years' time."

As I said last time they discovered the biggest prime number in September 2008:

If there is a pattern here, and in maths there usually is, it takes an average of 830 days to discover a new prime number, and the number of digits goes up by 48% each time, so the next prime number will have about 19 million digits and will be discovered on 5 January 2011.

So I was only wrong by two million digits and two years and a bit. Ah well.