864865 has 4 divisors (see below), whose sum is σ = 1037844. Its totient is φ = 691888.

The previous prime is 864817. The next prime is 864883. The reversal of 864865 is 568468.

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 147456 + 717409 = 384^2 + 847^2 .

It is a cyclic number.

It is not a de Polignac number, because 864865 - 2⁷ = 864737 is a prime.

It is an Ulam number.

It is a Duffinian number.

864865 is a lucky 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, 86482 + ... + 86491.

It is an arithmetic number, because the mean of its divisors is an integer number (259461).

2⁸⁶⁴⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

864865 is a deficient number, since it is larger than the sum of its proper divisors (172979).

864865 is a wasteful number, since it uses less digits than its factorization.

864865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172978.

The product of its digits is 46080, while the sum is 37.

The square root of 864865 is about 929.9811826053. The cubic root of 864865 is about 95.2758372832.

The spelling of 864865 in words is "eight hundred sixty-four thousand, eight hundred sixty-five".