11818181domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes that contain digits 1 and 8 only.at n=22A020456Smallest n-digit prime containing only digits 1 and 8, or 0 if no such prime exists.at n=7A036935Primes whose pattern of identical digits is unique among the primes.at n=3A374238Prime numbersat n=776895