810864 has 40 divisors (see below), whose sum is σ = 2328720. Its totient is φ = 270144.

The previous prime is 810853. The next prime is 810871. The reversal of 810864 is 468018.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

810864 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 7 ways as a sum of consecutive naturals, for example, 507 + ... + 1370.

It is an arithmetic number, because the mean of its divisors is an integer number (58218).

2⁸¹⁰⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

810864 is an abundant number, since it is smaller than the sum of its proper divisors (1517856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

810864 is a wasteful number, since it uses less digits than its factorization.

810864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1894 (or 1882 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 810864 is about 900.4798720682. The cubic root of 810864 is about 93.2501072145.

The spelling of 810864 in words is "eight hundred ten thousand, eight hundred sixty-four".