This is the 2000 digit prime number discovered recently by Dr John Cosgrave, a maths lecturer and head of mathematics at a Dublin College:
This is not the largest prime ever discovered but it is definitely the first found to be exactly 2000 digits - a significant figure for the millennium.
Having used his computer to search for prime numbers (to use in a course he teaches on cryptography and number theory) he compiled a list of over 300 numbers which he then checked for primes. He was actually on the lookout for a prime with at least a thousand digits - a "titanic" prime - and when he got to number 325 in the list chanced upon the millennium prime.
It is not the largest prime ever found (that has over 2 million digits in it) and it will not be the last - Euclid proved in the third century BC that there are an infinite number of primes.
To go to Dr John Cosgrove's home page- http://www.spd.dcu.ie/johnbcos
Source: The Guardian Newspaper