The newest largest prime number was recently discovered on the computer of a Great Internet Mersenne Prime Search (GIMPS) volunteer, Curtis Cooper. The number, as one would expect from something noted to be the largest of something, is quite large: 257,885,161-1. The fully expressed form has 17,425,170 digits, much larger than the previously discovered largest prime number, which measures in at 12,978,189 digits long. If kept in a plain text file, the new number results in a file size of 22.45MB.GIMPS is a collaborative research project performed over the internet where volunteers download some software and let their computers perform calculations. The current incarnation of the GIMPS network sports around 360,000 CPUs operating at 150 trillion calculations per second. The method GIMPS uses is similar to [email protected], another collaborative internet research project that is arguably more popular thanks to the help of the software being freely available on the PlayStation 3.The newly discovered number isn’t just a standard prime, but a Mersenne prime, and only the 48th of which ever discovered. Whereas a standard prime number is one that can only be divided by one and itself, a Mersenne prime takes the form of 2P-1, where P is a prime number.Large prime numbers require a lot of computing power to verify, and Mersenne primes are more complicated than a standard prime. So, aside from being just a fun thing to do with numbers, the Mersenne prime can be an effective tool to use when developing encryption.For all of Curtis’ computer’s hard work, he is eligible for a $3,000 prize. To check out the number, head on over here, where you have a choice to download the number in the full, in plain text or in gzip. The digits that bombard you on that page aren’t actually the full number, as 304,705 lines are left out. If you really want to see what your computer is made of, try copy-pasting portions of the number into text boxes. Better yet, see if you can send large portions of the numbers to friends through an instant message client.