2222929domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes that contain digits 2 and 9 only.at n=8A020460Smallest n-digit prime containing only digits 2 and 9, or 0 if no such prime exists.at n=6A036939Primes containing only two distinct digits whose sum of digits is 28, the second perfect number.at n=7A048518Prime numbersat n=164219