Primality proof for n = 6703903964971298549787012499102923063739682910296196688861780721860882015036773488400937149083451713845015929093243025426876941405973284973216824503041861:

Take b = 2.

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

471155737497642486266649722911997034941785580633861408520357030668404527002692877857903580176417856629449583072727858932500851 is prime.
b^((n-1)/471155737497642486266649722911997034941785580633861408520357030668404527002692877857903580176417856629449583072727858932500851)-1 mod n = 1936290063887191287122167552620170778951820607963661018372791834938945063290485332658863478484637471072873536751647209384207202385851116777505249688318443, which is a unit, inverse 20841944821106248778636693003022944346662930084631130753863116962725493150154406119016194639014832194168223483396831804170716500687519538721182521629534.

(471155737497642486266649722911997034941785580633861408520357030668404527002692877857903580176417856629449583072727858932500851) divides n-1.

(471155737497642486266649722911997034941785580633861408520357030668404527002692877857903580176417856629449583072727858932500851)^2 > n.

n is prime by Pocklington's theorem.