864561 has 8 divisors (see below), whose sum is σ = 1165024. Its totient is φ = 570240.

The previous prime is 864551. The next prime is 864581. The reversal of 864561 is 165468.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 864561 - 2⁹ = 864049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (864511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1195 + ... + 1776.

It is an arithmetic number, because the mean of its divisors is an integer number (145628).

2⁸⁶⁴⁵⁶¹ is an apocalyptic number.

It is an amenable number.

864561 is a deficient number, since it is larger than the sum of its proper divisors (300463).

864561 is a wasteful number, since it uses less digits than its factorization.

864561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3071.

The product of its digits is 5760, while the sum is 30.

The square root of 864561 is about 929.8177240728. The cubic root of 864561 is about 95.2646728245.

The spelling of 864561 in words is "eight hundred sixty-four thousand, five hundred sixty-one".