An emirp ("prime" spelled backwards) is a prime whose (base 10) reversal is also prime, but which is not a palindromic prime. The first few are 13, 17, 31, 37, 71, 73, 79, 97, 107, 113, 149, 157, ... (OEIS A006567). A binary plot of the emirps is illustrated above.
Emirp
See also
Emirpimes, Palindromic Prime, Prime Number, ReversalExplore with Wolfram|Alpha
References
Gardner, M. The Magic Numbers of Dr Matrix. Buffalo, NY: Prometheus, p. 230, 1985.Rivera, C. "Problems & Puzzles: Puzzle 020-Reversible Primes." http://www.primepuzzles.net/puzzles/puzz_020.htm.Sloane, N. J. A. Sequence A006567/M4887 in "The On-Line Encyclopedia of Integer Sequences."Referenced on Wolfram|Alpha
EmirpCite this as:
Weisstein, Eric W. "Emirp." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Emirp.html