864921 has 4 divisors (see below), whose sum is σ = 1153232. Its totient is φ = 576612.

The previous prime is 864917. The next prime is 864947. The reversal of 864921 is 129468.

864921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 864921 - 2² = 864917 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 864921.

It is not an unprimeable number, because it can be changed into a prime (864901) 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, 144151 + ... + 144156.

It is an arithmetic number, because the mean of its divisors is an integer number (288308).

2⁸⁶⁴⁹²¹ is an apocalyptic number.

It is an amenable number.

864921 is a deficient number, since it is larger than the sum of its proper divisors (288311).

864921 is a wasteful number, since it uses less digits than its factorization.

864921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288310.

The product of its digits is 3456, while the sum is 30.

The square root of 864921 is about 930.0112902540. The cubic root of 864921 is about 95.2778936087.

The spelling of 864921 in words is "eight hundred sixty-four thousand, nine hundred twenty-one".