Sieved to P=160G

Primality testing 2^121839-7 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 11
Running N-1 test using base 29
Running N+1 test using discriminant 41, base 10+sqrt(41)
Calling N-1 BLS with factored part 0.62% and helper 0.02% (1.88% proof)
2^121839-7 is Fermat and Lucas PRP! (523.5040s+0.0035s)

To be completed...