Belphegor’s prime (1000000000000066600000000000001) is a palindromic prime number that features the number 666 in the middle and 13 zeroes either side.
Discovered by electrical engineer and mathematician Harvey Dubner, the number was given its name by American author Clifford Pickover who named it after a Devil associated with one of the seven deadly sins, and he helps people make discoveries.
But in order to find this, Dubner started with the prime number 1661. From there, he added zeroes on either side of the 666 to create “Belphegor numbers”. So the first five Belphegor numbers are:
- 1661
- 106601
- 100666001
- 10006660001
- 100006660001
(h/t Futility Closet)
Filed under: numbers