Multipling 6666666 by its sum of digits (42), we get a palindrome (279999972).
6666666 is nontrivially palindromic in base 10.
It is a nude number because it is divisible by every one of its digits.
6666666 is a nontrivial repdigit in base 10.
It is a plaindrome in base 10.
It is a nialpdrome in base 10.
It is a zygodrome in base 10.
It is an unprimeable number.
Almost surely, 26666666 is an apocalyptic number.
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
6666666 is a wasteful number, since it uses less digits than its factorization.
6666666 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 4893.
The square root of 6666666 is about 2581.9887683722. The cubic root of 6666666 is about 188.2071995026.
The spelling of 6666666 in words is "six million, six hundred sixty-six thousand, six hundred sixty-six".