Belphegor's Prime

Belphegor's prime is the name for the number 1,000,000,000,000,066,600,000,000,000,001 = 1030+666⋅1014+1. It is a palindromic prime, notable for its curious decimal expansion containing the beast number. Clifford Pickover named the number after a demon from the Judeo-Christian mythos, playing on 666's association with the devil in numerology.