other names · Added 9 October 2026
Belphegor's prime
Palindromic prime number
Belphegor's prime is the palindromic prime number 1000000000000066600000000000001 (1030 + 666 × 1014 + 1), a number which reads the same both backwards and forwards and is only divisible by itself and one.
From Wikipedia (CC BY-SA). Not a dictionary word, so it lives in Other Names.
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