864009 has 6 divisors (see below), whose sum is σ = 1248026. Its totient is φ = 576000.

The previous prime is 864007. The next prime is 864011. The reversal of 864009 is 900468.

864009 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (864007) and next prime (864011).

It can be written as a sum of positive squares in only one way, i.e., 585225 + 278784 = 765^2 + 528^2 .

It is not a de Polignac number, because 864009 - 2¹ = 864007 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (864007) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 47992 + ... + 48009.

2⁸⁶⁴⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

864009 is a deficient number, since it is larger than the sum of its proper divisors (384017).

864009 is a wasteful number, since it uses less digits than its factorization.

864009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96007 (or 96004 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 864009 is about 929.5208443064. The cubic root of 864009 is about 95.2443938255.

It can be divided in two parts, 86 and 4009, that added together give a triangular number (4095 = T₉₀).

The spelling of 864009 in words is "eight hundred sixty-four thousand, nine".