Equal to the form 2*k*R(270343)+1, where R(p) is a base 10 Repunit with the exponent p. It was a candidate for a factor of the double Repunit R(R(270343)).
Sieved with srsieve, PRP tested with LLR v3.8.9

48358*10^270343-48357 is strong-Fermat and Lucas PRP, Starting Frobenius test sequence
48358*10^270343-48357 is strong-Fermat, Lucas and Frobenius PRP! (P = 4, Q = 2, D = 8) Time : 16566.541 sec.

187322*10^270343-187321 is base 3-Strong Fermat PRP! Time : 2791.457 sec.
187322*10^270343-187321 is strong-Fermat and Lucas PRP, Starting Frobenius test sequence
187322*10^270343-187321 is strong-Fermat, Lucas and Frobenius PRP! (P = 5, Q = 2, D = 17) Time : 12356.360 sec.

To be completed...