866004 has 12 divisors (see below), whose sum is σ = 2020704. Its totient is φ = 288664.

The previous prime is 866003. The next prime is 866009. The reversal of 866004 is 400668.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36072 + ... + 36095.

It is an arithmetic number, because the mean of its divisors is an integer number (168392).

2⁸⁶⁶⁰⁰⁴ is an apocalyptic number.

It is an amenable number.

866004 is an abundant number, since it is smaller than the sum of its proper divisors (1154700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

866004 is a wasteful number, since it uses less digits than its factorization.

866004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72174 (or 72172 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 866004 is about 930.5933590995. The cubic root of 866004 is about 95.3176440295.

The spelling of 866004 in words is "eight hundred sixty-six thousand, four".