PFGW Version 3.7.10.64BIT.20150809.x86_Dev [GWNUM 28.7]

No factoring at all, not even trivial division
Primality testing 2^216091-1666389 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 2
Running N-1 test using base 11
Running N+1 test using discriminant 17, base 1+sqrt(17)
2^216091-1666389 is Fermat and Lucas PRP! (1168.3033s+0.0002s)

To be completed...