Primality testing Phi(11971,89) [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 2
Running N+1 test using discriminant 7, base 1+sqrt(7)
Calling N-1 BLS with factored part 25.64% and helper 0.32% (77.25% proof)
Phi(11971,89) is Fermat and Lucas PRP! (394.8081s+0.0009s)