Boffins have spent years looking for the mind-boggling long number since the Electronic Frontier Foundation set-up a $100,000 prime number prize to promote co-operative computing on the Internet.

A team from the University of California discovered the whopping number which can be divided only by itself and one by linking 75 computers over the internet.

This means they were able to use the combined calculating power of the machines to find and verify the new prime.

Luckily the team can email in their entry - it would take two and a half months to write out by hand and even printing out all 13 million digits in a normal size font would create a number 30 miles long.