866566664 has 16 divisors (see below), whose sum is σ = 1625125200. Its totient is φ = 433199952.

The previous prime is 866566633. The next prime is 866566697. The reversal of 866566664 is 466665668.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73379 + ... + 84365.

It is an arithmetic number, because the mean of its divisors is an integer number (101570325).

Almost surely, 2^866566664 is an apocalyptic number.

It is an amenable number.

866566664 is a deficient number, since it is larger than the sum of its proper divisors (758558536).

866566664 is a wasteful number, since it uses less digits than its factorization.

866566664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20852 (or 20848 counting only the distinct ones).

The product of its digits is 7464960, while the sum is 53.

The square root of 866566664 is about 29437.5043779190. The cubic root of 866566664 is about 953.3828296251.

The spelling of 866566664 in words is "eight hundred sixty-six million, five hundred sixty-six thousand, six hundred sixty-four".