How to discover your own prime number

Although prime numbers can have cryptographic uses, the vast size of M74207281 rules it out for that goal.

If it’s been a while since you thought about a prime number, primes are numbers with whole number factors that are only one and itself. The previous longest prime, found in 2013, was 2 – 1, five million digits shorter than the new champ.

Cooper also discovered the previous record holder in February 2013, which was 2 – 1, a number with more than 17 million digits, along with two other older records.

The search for ever larger primes has nearly a tradition in mathematics, it comes, inter alia, to test the performance of computer – and to have fun.

More simple prime numbers include, 2,3,5,7 and 13, but the search is on to find huge prime numbers, millions of digits long.

There are an infinite amount of prime numbers, so there is no such thing as the biggest one – but the latest discovery is the largest known to man. Larger prime numbers are increasingly rare, which is why mathematicians are competing to find them.

It was made by Curtis Cooper, a mathematician at the University of Central Missouri, whose computer discovered the number back in September, but didn’t notify him until now. They are the easiest large primes to find since they provide numbers to aim for, and there’s a quick way to test they are prime. Mainly primes are found using computers, but they are said to be “discovered” when a person notices and reports it. A bug kept the software from sending out an alert email, so the number went undiscovered by humans for months.

To prove there were no errors in the prime discovery process, the prime was independently verified by two computer programs and different hardware. He has received a $3000 prize from GIMPS for each discovery. Not only because they’re so pure – their defining characteristic is that they’re only divisible by themselves and one – but also because they can be used to create all sorts of fascinating patterns, such as the Ulam spiral.

Mersenne primes were named for the French monk Marin Mersenne, who studied these numbers more than 350 years ago.

“This prime is too large to now be of practical value”, the Gimps project admitted in a statement.