864440 has 16 divisors (see below), whose sum is σ = 1945080. Its totient is φ = 345760.

The previous prime is 864439. The next prime is 864449. The reversal of 864440 is 44468.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (864449) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10766 + ... + 10845.

2⁸⁶⁴⁴⁴⁰ is an apocalyptic number.

It is an amenable number.

864440 is an abundant number, since it is smaller than the sum of its proper divisors (1080640).

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

864440 is a wasteful number, since it uses less digits than its factorization.

864440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21622 (or 21618 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 26.

The square root of 864440 is about 929.7526552799. The cubic root of 864440 is about 95.2602283480.

The spelling of 864440 in words is "eight hundred sixty-four thousand, four hundred forty".