66881 is nontrivially palindromic in base 2 and base 4.
It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18866 = 2 ⋅9433.
It is a cyclic number.
It is a Duffinian number.
It is a plaindrome in base 6 and base 13.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 66881.
266881 is an apocalyptic number.
It is an amenable number.
66881 is a wasteful number, since it uses less digits than its factorization.
66881 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 1470.
The square root of 66881 is about 258.6136113974. The cubic root of 66881 is about 40.5914207729.
The spelling of 66881 in words is "sixty-six thousand, eight hundred eighty-one".