Largest Prime Number Ever Identified

Mathematicians have found the largest prime number ever identified - which is 17 million digits long.

The new record holder and its predecessor, discovered in 2008, were both found using a vast network of computers dubbed the Great Internet Mersenne Prime Search (Gimps).

George Woltman, the scientist who created the Gimps network, said the task of finding a new prime number is "analogous to climbing Mount Everest".

He told Scientific American: "People enjoy it for the challenge of the discovery of finding something that's never been known before."

The number was discovered by mathematicians at the University of Central Missouri.

A different computer system running on different hardware confirmed that it is a prime number.

Prime numbers are numbers that cannot be divided by any numbers other than themselves or one to generate a whole number.

It is the third Mersenne prime discovered by the university, and the 48th ever discovered.

Mersenne primes are named after their discoverer, 17th century French mathematician Marin Mersenne.

They are expressed as 2P-1, or two to the power of "P'' minus one. P itself is a prime number. For the new prime, P is 57,885,161.

The research team will be awarded a $3,000 (£1,900) prize from Gimps for the discovery, while the Electronic Frontier Foundation has offered $150,000 (£95,000) for the first 100 million digit prime number to be found.