Largest Prime Discovered to Be 22 Million Digits Long
It took one computer a month to find the largest prime number; a number that is 22 million digits long.
The number, 274,207,281 - 1, is a Mersenne prime, a class of primes which are close to exponentials of 2. Arriving at such large numbers is no mean task for most computers today. The discovery of the number thus is a record for the Great Internet Mersenne Prime Search, which hopes to find such primes. The computer that performed the calculation was provided by Curtis Cooper of University of Missouri, according to CNET.
Prime numbers fascinate mathematicians as they are increasingly rare to find when the count increases. Mersenne primes are rarer. They are named so after the French monk Marin Mersenne who studied them more than three centuries ago. Only 49 have been known.
Primes are useful in cryptographic applications but the 22 million digits in the latest prime make it too big for any practical use.
"While prime numbers are important for cryptography, this prime is too large to currently be of practical value. However, the search itself does have several practical benefits. Historically, searching for Mersenne primes has been used as a test for computer hardware. Earlier this month, GIMPS' prime95 software and members of a German computing community uncovered a flaw in Intel's latest Skylake CPUs. Prime95 has also discovered hardware problems in many individual's PCs," GIMPS website reads while announcing the discovery.