71777777777domain: NAppears in sequencesSmallest prime whose product of digits is 7^n.at n=10A090841Smallest prime numbers p of length n having a decimal expansion x(1)x(2)... x(n) such that there exists an index j where x(j) = 1 and x(i) = 7 for i<>j, or 0 if no such prime exists.at n=9A241027