18/01/2018

The world's largest prime number has 23 million digits.

American electrical engineer Jonathan Pace, 51, had a dream: to discover the largest prime number in the world. For 14 years he ran software on his computer with this goal in mind. His persistence paid off and came as a (belated) Christmas present.

On December 26, 2017, he discovered 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, the Mersenne primes, which follow the form 2 ^{^n} – 1.

Since 1588, humanity has only found 49 cousins of this family. The number detected by Pace is the fiftieth and was obtained with the formula 2 ^{77,232,917 –} 1 and has 23,249,425 digits — almost a million more than the previous record, obtained two years ago.

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

The engineer kept a personal computer running for six days straight to prove that 2 ^{77232917 –} 1 is a prime number. For the discovery, he will receive a reward of $3,000 (approximately R$9,700).

To learn more about the M77232917 and its 49 predecessors, click here.