A Belphegor prime (also known as a Beelphegor prime) is a prime Belphegor number, i.e., a palindromic
prime of the form 
.
The first few Belphegor primes are the Belphegor
numbers
 |
with 
,
13, 42, 506, 608, 2472, 2623, 28291, 181298, ... (OEIS A232448).
Shifting this sequence by one gives 1, 14, 43, 507, 609, ... (OEIS A156166).
The above definition generalizes the original definition due to Pickover, who named
 |
"the" Belphegor prime after one of the Seven Princes of Hell who is the demon of inventiveness. This prime has a number of numerological properties, including a central beast number 666 which is surrounded on each side by 13 (a number traditionally associated with bad luck) zeros and an overall decimal number length of 31-which is 13 backwards.
