864820 has 24 divisors (see below), whose sum is σ = 1981728. Its totient is φ = 314400.

The previous prime is 864817. The next prime is 864883. The reversal of 864820 is 28468.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1746 + ... + 2185.

It is an arithmetic number, because the mean of its divisors is an integer number (82572).

2⁸⁶⁴⁸²⁰ is an apocalyptic number.

It is an amenable number.

864820 is an abundant number, since it is smaller than the sum of its proper divisors (1116908).

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

864820 is a wasteful number, since it uses less digits than its factorization.

864820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3951 (or 3949 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 864820 is about 929.9569882527. The cubic root of 864820 is about 95.2741848145.

It can be divided in two parts, 8648 and 20, that added together give a palindrome (8668).

The spelling of 864820 in words is "eight hundred sixty-four thousand, eight hundred twenty".