Breaking news! A few days ago a supercomputer in Missouri discovered the largest known prime number:
It is around 22 million digits long – 5 million digits longer than the previous largest known prime (!), which was discovered January 2013.
This prime number is called a Mersenne prime, as it is in the form:
Named after the French monk Marin Mersenne who studied their properties 350 years ago, they’re the easiest large primes to find as they give researches numbers to aim for and it’s easy to test whether or not they are prime.
This new prime was discovered by Curtis Cooper at the University of Central Missouri, according to the General Internet Mersenne Prime Search (GIMPS). In fact, this is the fourth time Dr Cooper has found the new largest prime! GIMPS is the longest continuously running distributed computing project; it has been finding prime numbers since 1996, and has thus far discovered the 15 largest Mersenne primes.
You may ask, what is the point? Although it is too soon for this number to have any practical value, prime numbers do play a hugely important role in computer encryption, which is used to keep certain functions online (including online banking, private messages and shopping transactions) safe. Yes, we are far from ‘using up’ all the primes, but finding new ones is essential to ensure we continue to have enough ‘keys’ for our encryption. And since the number of primes is infinite, the search will continue!