Primality proof for n = 3369993333393829974333376885877453834204643052817571560137951281149:

Take b = 2.

b^(n-1) mod n = 1.

4815314615204347717321 is prime.
b^((n-1)/4815314615204347717321)-1 mod n = 272285484880433246875123841545220862667833984438329314472636416668, which is a unit, inverse 1076336479328688023588995199774978696319391506967592484433285537656.

671165898617413417 is prime.
b^((n-1)/671165898617413417)-1 mod n = 2154364817100898442914486529928944965964227607981441785482861499093, which is a unit, inverse 1162552313677990867869695722219886219211684897093822833449075855231.

(671165898617413417 * 4815314615204347717321) divides n-1.

(671165898617413417 * 4815314615204347717321)^2 > n.

n is prime by Pocklington's theorem.