1117111111domain: NAppears in sequencesLeast n-digit prime using digit 7 once and rest all 1, or 0 if no such prime exists.at n=9A090535Primes with digital product = 7.at n=13A107693Lesser of two consecutive primes such that the product of its digits is also prime and the sum of the digits of the other is composite.at n=19A370848