Largest prime number ever discovered

The largest prime number has been discovered so far, a number that can only be shared by one and itself.

The record number was announced by the Great Internet Mersenne Prime Search (GIMPS), a collective search for such extreme numbers. A computer needed six days of non-stop counting to find the number. Then it was calculated with four different programs on four different computers. Whoever prints the prime number can fill 9000 book pages. 'And if you enter five digits every second within 2.5 cents every second, you have the 118-kilometer length 54 days later,' says GIMPS.

The record number was discovered by a volunteer from the United States, who had made his computer available for the search. He may receive a reward of 3000 dollars, converted about 2500 euros. GIMPS hopes to find a prime number of 100 million digits.