With decimal expansion 99...99799...997, it is a PRP member of a near-repdigit twin pair; 10^31047-2*10^26802-1 = 99...99799...999 is prime. Found with an ad hoc twin sieve and then PFGW.

Primality testing 10^31047-2*10^26802-3 [N-1/N+1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 2
Running N+1 test using discriminant 5, base 5+sqrt(5)
Calling N-1 BLS with factored part 0.00% and helper 0.00% (0.02% proof)
10^31047-2*10^26802-3 is Fermat and Lucas PRP! (200.0964s+0.0024s)

Primality testing 10^31047-2*10^26802-1 [N+1, Brillhart-Lehmer-Selfridge]
Running N+1 test using discriminant 3, base 1+sqrt(3)
Calling Brillhart-Lehmer-Selfridge with factored part 60.34%
10^31047-2*10^26802-1 is prime! (140.0281s+0.0027s)

To be completed...