Math enthusiasts rejoice – there is a new prime number on the block!

The mathematics news for this New Year is the discovery of a new prime number – the largest ever recorded. A prime number is greater than 1 and has no positive divisors other than 1 and itself, such as 7. Prime numbers differ from composite numbers (like 6), which have more than 1 factor pair (6 has the factor pairs 1 & 6 and 2 & 3).

Cryptography, the field of writing or breaking codes, relies on prime numbers to create encryption – a secret language through which information is stored and sent – and decryption – the method by which a code is broken. Examples of this information could be the data stored in a credit card chip or even Internet passwords. Many exciting STEM-oriented careers require candidates who are at least familiar with cryptography. Imagine being the officer in charge of U.S. Navy submarine or securing a position as a cyber-security specialist who is responsible for thwarting hacker threats.

Prime Number

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On January 7, the Great Internet Mersenne Prime Search, or GIMPS, revealed that its 20th anniversary was marked by the discovery of the largest known prime number, M742047281, which was identified by a computer on September 17, 2015. Though the number – which is also the 49th Mersenne Prime – uses the name M742047281, the full figure includes 22,338,618 numerals, which GIMPS reveals is nearly 5 million digits longer than the former record holder. Excitement lies not only in its discovery, but also in its status as a Mersenne prime number, the rare figures that are named for Marin Mersenne, a French monk who studied them. “A Mersenne prime is a prime of the form 2P-1,” according to GIMPS. “The first Mersenne primes are 3, 7, 31, 127 (corresponding to P = 2, 3, 5, 7). There are only 49 known Mersenne primes.” Considering Mersenne primes are found through the formula 2P-1, it’s no wonder that M742047281’s is also known as 274,207,281-1.

During an interview with GIMPS, Professor Curtis Cooper, whose team has previously discovered three Mersenne prime numbers, said, “I just feel lucky and it’s as exciting the fourth time here as the first time.” Cooper also reveals that there are approximately 800 computers at the University of Central Missouri through which his team is running GIMPS in search of Mersenne prime numbers. While the number is so large and the figure will probably not serve an additional purpose, other than as a stepping stone toward the next prime number discovery, Dr. Cooper is excited about his team’s success.

Contribute to this exciting prime number research by visiting the GIMPS website and downloading the complimentary software – or ask a teacher to incorporate this project into a class assignment.