229727domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumbers k such that k and k^2 use only the digits 2, 4, 5, 7 and 9.at n=19A137098Primes that cannot become a different prime under any mapping of some single decimal digit <=> with some other single decimal digit.at n=32A180561Prime numbersat n=20412