The Largest Prime Number Ever Found and the 52nd Mersenne Prime …

Today is a special day for cybersecurity, and where the largest known Mersenne prime has been found … 2¹³⁶²⁷⁹⁸⁴¹-1. The largest found previous one was 2⁸²⁵⁸⁹⁹³³-1, and which was the 51st Mersenne prime ever found. Since 1997, the GIMPS (Great Internet Mersenne Prime Search) distributed system has been used to find prime numbers, and it took six years to find it using the GIMPS software and the first to use GPUs. It has over 42 million digits, and starts with:

In April 2021, it stopped using the Lucas-Lehmer method, and moved on to the Fermat PRobable Prime (PRP) Test. This uses:

and where p is a prime number. Here is an example:

>>> a=2
>>> p=2**19-1
>>> if (pow(a,p-1,p)==1): print ("It is prime")
It is prime

The announcement is here: