It is a plaindrome in base 10.
It is a zygodrome in base 10.
It is a congruent number.
It is an unprimeable number.
It is a self-describing number.
Almost surely, 266666688888888 is an apocalyptic number.
It is an amenable number.
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
66666688888888 is a wasteful number, since it uses less digits than its factorization.
66666688888888 is an evil number, because the sum of its binary digits is even.
The spelling of 66666688888888 in words is "sixty-six trillion, six hundred sixty-six billion, six hundred eighty-eight million, eight hundred eighty-eight thousand, eight hundred eighty-eight".