On 24 December 2019, 01:28:13 UTC, PrimeGrid's Extended Sierpinski Problem found the Mega Prime:
The prime is 4,220,176 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 20th overall. This find eliminates k=99739; 9 k's remain in the Extended Sierpinski Problem.
The discovery was made by Brian D. Niegocki (Penguin) of the United States using an Intel(R) Xeon(R) Gold 6140 CPU @ 2.30GHz with 1GB RAM, running Linux Ubuntu. This computer took about 14 hours, 14 minutes to complete the primality test using LLR. Brian is a member of the Antarctic Crunchers team.
The prime was verified on 24 December 2019, 04:37:31 UTC by Pavel Atnashev (Pavel Atnashev) of Russia using an Intel(R) Xeon(R) E5-2680 v2 @ 2.80GHz with 8GB RAM, running Linux. This computer took about 4 hours, 6 minutes to complete the primality test using LLR. Pavel is a member of the Ural Federal University team.
For more details, please see the official announcement.