On 20 August 2016, 16:21:09 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=180062 by finding the mega prime:
The prime is 1,572,123 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 48th overall. This is the largest known base 5 mega prime. 74 k's now remain in the Riesel Base 5 Problem.
The discovery was made by Stefan Larsson (288larsson) of Sweden using an Intel(R) Core(TM) i7-5775C CPU @ 3.30GHz with 8GB RAM running Linux. This computer took about 14 hours 3 minutes to complete the primality test using LLR. Stefan is a member of the Sicituradastra. team.
For more details, please see the official announcement.