866644206404 has 48 divisors (see below), whose sum is σ = 1556144206848. Its totient is φ = 422087990688.

The previous prime is 866644206403. The next prime is 866644206431. The reversal of 866644206404 is 404602446668.

It is a super-2 number, since 2×866644206404² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (866644206403) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 174477929 + ... + 174482895.

It is an arithmetic number, because the mean of its divisors is an integer number (32419670976).

Almost surely, 2^866644206404 is an apocalyptic number.

It is an amenable number.

866644206404 is a deficient number, since it is larger than the sum of its proper divisors (689500000444).

866644206404 is a wasteful number, since it uses less digits than its factorization.

866644206404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7584 (or 7582 counting only the distinct ones).

The product of its (nonzero) digits is 5308416, while the sum is 50.

The spelling of 866644206404 in words is "eight hundred sixty-six billion, six hundred forty-four million, two hundred six thousand, four hundred four".