864240 has 80 divisors (see below), whose sum is σ = 2895648. Its totient is φ = 211968.

The previous prime is 864223. The next prime is 864251. The reversal of 864240 is 42468.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 864240.

It is a congruent number.

It is an unprimeable number.

864240 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2982 + ... + 3258.

2⁸⁶⁴²⁴⁰ is an apocalyptic number.

864240 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 864240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1447824).

864240 is an abundant number, since it is smaller than the sum of its proper divisors (2031408).

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

864240 is a wasteful number, since it uses less digits than its factorization.

864240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306 (or 300 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 864240 is about 929.6450935707. The cubic root of 864240 is about 95.2528811964.

The spelling of 864240 in words is "eight hundred sixty-four thousand, two hundred forty".