6864021 has 24 divisors (see below), whose sum is σ = 10518144. Its totient is φ = 4471200.

The previous prime is 6864019. The next prime is 6864031. The reversal of 6864021 is 1204686.

It is not a de Polignac number, because 6864021 - 2¹ = 6864019 is a prime.

It is a super-2 number, since 2×6864021² = 94229568576882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6864031) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11121 + ... + 11721.

It is an arithmetic number, because the mean of its divisors is an integer number (438256).

Almost surely, 2^6864021 is an apocalyptic number.

It is an amenable number.

6864021 is a deficient number, since it is larger than the sum of its proper divisors (3654123).

6864021 is an equidigital number, since it uses as much as digits as its factorization.

6864021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 663 (or 651 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 6864021 is about 2619.9276707573. The cubic root of 6864021 is about 190.0463506493.

The spelling of 6864021 in words is "six million, eight hundred sixty-four thousand, twenty-one".