864556 has 36 divisors (see below), whose sum is σ = 1924776. Its totient is φ = 336000.

The previous prime is 864551. The next prime is 864581. The reversal of 864556 is 655468.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (864551) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1956 + ... + 2356.

It is an arithmetic number, because the mean of its divisors is an integer number (53466).

2⁸⁶⁴⁵⁵⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 864556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (962388).

864556 is an abundant number, since it is smaller than the sum of its proper divisors (1060220).

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

864556 is a wasteful number, since it uses less digits than its factorization.

864556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430 (or 421 counting only the distinct ones).

The product of its digits is 28800, while the sum is 34.

The square root of 864556 is about 929.8150353699. The cubic root of 864556 is about 95.2644891767.

The spelling of 864556 in words is "eight hundred sixty-four thousand, five hundred fifty-six".