On 25 August 2017, 04:39:57 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=171362 by finding the mega prime:
The prime is 1,678,230 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 57th overall. 73 k's now remain in the Riesel Base 5 Problem.
The discovery was made by Frank Schwegler (Frank Schwegler) of the United States using an Intel(R) Core(TM) i7-5820K CPU @ 3.30GHz with 16GB RAM running Microsoft Windows 7 Ultimate Edition. This computer took about 40 hours 12 minutes to complete the primality test using LLR.
The prime was verified on 26 August 2017 04:44:17 UTC by Sam Omlotek (SamO) of the United States using an Intel(R) Core(TM) i5-2500S CPU @ 2.70GHz with 8GB RAM, running macOS Sierra. This computer took about 44 hours 35 minutes to complete the primality test using LLR. Sam is a member of the DONTPANIC team.
For more details, please see the official announcement.