18/01/2018

Largest prime number in the world has 23 million digits

The American electrical engineer, Jonathan Pace, 51, had a dream: to discover the largest prime number in the world. For 14 years he ran a computer software for that purpose. It eventually paid off and came as a (late) Christmas present.

On December 26, 2017, he found out the largest prime number ever cataloged by mathematicians. Named M77232917, it has more than 23 million digits. The number found by Pace belongs to a special family of prime numbers, that of the Mersenne cousins, which obey the 2ⁿ – 1 form.

Since 1588, mankind has only found 49 cousins of this family. The number detected by Pace is the fiftieth, was obtained with the formula 2^{77.232.917 –} 1 and has 23,249,425 digits — almost one million more than the previous record from two years ago.

Pace is one of Internet Mersenne Prime Search’s (GIMPS) thousands of volunteers of a collaborative project to search for Mersenne prime numbers through a free program developed by computer scientists George Woltman, Scott Kurowski and Aaron Blosser.

The engineer kept a personal computer working for six days nonstop to prove that 2^{77,232,917 –} 1 is a prime number. He will receive US$ 3,000 reward for the discovery.

If you want to have a closer look at M77232917 and its 49 predecessors, click here