66855866 has 32 divisors (see below), whose sum is σ = 132388992. Its totient is φ = 24514560.

The previous prime is 66855827. The next prime is 66855881.

66855866 is nontrivially palindromic in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10151 + ... + 15386.

It is an arithmetic number, because the mean of its divisors is an integer number (4137156).

Almost surely, 2^66855866 is an apocalyptic number.

66855866 is a deficient number, since it is larger than the sum of its proper divisors (65533126).

66855866 is a wasteful number, since it uses less digits than its factorization.

66855866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25574.

The product of its digits is 2073600, while the sum is 50.

The square root of 66855866 is about 8176.5436463092. The cubic root of 66855866 is about 405.8633535954.

The spelling of 66855866 in words is "sixty-six million, eight hundred fifty-five thousand, eight hundred sixty-six".