the palindromic prime 1000000000000066600000000000001 is known as Belphegor's Prime, named after #Belphegor, one of the seven princes of Hell. Belphegor's Prime consists of the number 666, on either side enclosed by thirteen zeroes and a one. Belphegor's Prime is an example of a beastly #palindromic #prime in which a prime p is palindromic with 666 in the center. #calculotrivia #maths #Math