A prime number is a positive integer greater than one which can only be evenly divided by itself and the number one. Around 300 BC, Euclid proved that there are infinitely many prime numbers. By the early 17th century, mathematicians defined a Mersenne prime to be a prime number that is one less than a power of two. That is, it is a prime number that can be written in the form Mn = 2n − 1 for some integer n. Since then, many mathematicians have searched for large prime numbers. In January 2016, a team led by Dr. Curtis Cooper at the University of Central Missouri announced that they have found the largest known prime number to date — it is 2^74,207,281 – 1, it has over 22.3 million digits! It's the 49th Mersenne prime. The new record has broken the old record by approximately 5 million digits discovered by the same UCM team in 2013. The number was computed by a UCM computer and discovered by data-mining. Dr. Cooper doesn’t plan to discontinue his research into primes anytime in the near future.
