Found with PFGW Version 3.7.5

1790^6671-6671^1790 is 2-PRP! (20.1391s+0.0028s)
1790^6671-6671^1790 is 3-PRP! (17.6821s+0.0029s)
1790^6671-6671^1790 is 5-PRP! (18.6789s+0.0023s)
1790^6671-6671^1790 is 7-PRP! (20.2757s+0.0021s)
1790^6671-6671^1790 is 11-PRP! (21.4530s+0.0037s)

Primality testing 1790^6671-6671^1790 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 3
Running N+1 test using discriminant 19, base 1+sqrt(19)
Calling N+1 BLS with factored part 0.14% and helper 0.02% (0.44% proof)
1790^6671-6671^1790 is Fermat and Lucas PRP! (96.1189s+0.0037s)

To be completed...