866645 has 16 divisors (see below), whose sum is σ = 1142400. Its totient is φ = 627264.

The previous prime is 866641. The next prime is 866653. The reversal of 866645 is 546668.

It is a cyclic number.

It is not a de Polignac number, because 866645 - 2² = 866641 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866641) 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 15 ways as a sum of consecutive naturals, for example, 4256 + ... + 4454.

It is an arithmetic number, because the mean of its divisors is an integer number (71400).

2⁸⁶⁶⁶⁴⁵ is an apocalyptic number.

It is an amenable number.

866645 is a deficient number, since it is larger than the sum of its proper divisors (275755).

866645 is a wasteful number, since it uses less digits than its factorization.

866645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284.

The product of its digits is 34560, while the sum is 35.

The square root of 866645 is about 930.9376993118. The cubic root of 866645 is about 95.3411556766.

The spelling of 866645 in words is "eight hundred sixty-six thousand, six hundred forty-five".