Found with PFGW Version 3.4.8

2121^3140-3140^2121 is 2-PRP! (23.2396s+0.0094s)
2121^3140-3140^2121 is 3-PRP! (25.5075s+0.0120s)
2121^3140-3140^2121 is 5-PRP! (26.5045s+0.0120s)
2121^3140-3140^2121 is 7-PRP! (25.6812s+0.0138s)
2121^3140-3140^2121 is 11-PRP! (26.7413s+0.0118s)

Primality testing 2121^3140-3140^2121 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 7
Running N-1 test using base 11
Running N-1 test using base 23
Running N+1 test using discriminant 31, base 3+sqrt(31)
Calling N-1 BLS with factored part 0.05% and helper 0.03% (0.19% proof)
2121^3140-3140^2121 is Fermat and Lucas PRP! (172.8558s+0.0173s)

To be completed...