864665 has 4 divisors (see below), whose sum is σ = 1037604. Its totient is φ = 691728.

The previous prime is 864641. The next prime is 864673. The reversal of 864665 is 566468.

864665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 364816 + 499849 = 604^2 + 707^2 .

It is a cyclic number.

It is not a de Polignac number, because 864665 - 2¹⁰ = 863641 is a prime.

It is a Duffinian number.

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, 86462 + ... + 86471.

It is an arithmetic number, because the mean of its divisors is an integer number (259401).

2⁸⁶⁴⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

864665 is a deficient number, since it is larger than the sum of its proper divisors (172939).

864665 is a wasteful number, since it uses less digits than its factorization.

864665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172938.

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

The square root of 864665 is about 929.8736473306. The cubic root of 864665 is about 95.2684925391.

The spelling of 864665 in words is "eight hundred sixty-four thousand, six hundred sixty-five".