- They are a special category of prime numbers — which are unique for being divisible by nothing other than 1 and themselves — of the form 2n – 1.
- They are named for the French monk Marin Mersenne, who studied these numbers more than 350 years ago.
- There are infinite prime numbers but they get increasingly harder to find. Recently, a 20-year-old collaboration of computers, called GIMPS (Great Internet Mersenne Prime Search) that works by pooling in computing power discovered the largest prime number ever. It turned out that this number was also a Mersenne prime and is only the 50th known prime of this form.
- The number 277232,917 – 1 has 23,249,425 digits and is a million digits larger than the previous record holder.
- A computer volunteered by Jonathan Pace made the find on December 26, 2017 and he is one of thousands of volunteers using free GIMPS software.
- Proving that this number was indeed a prime took six days of non-stop computing on a PC with an Intel i5-6600 CPU. To prove there were no errors in the prime discovery process, the new prime was independently verified using four different programs on four different hardware configurations.