12101111

Appears in sequences

• Composite numbers whose prime factors contain no digits other than 0 and 1.at n=21A036928
• Numbers n such that the set S(n) = {k: k + reverse(k) = n} is not empty, at least one element of S(n) has the same number of digits as n and at least one element of S(n) has one digit less than n has.at n=18A088171