6807921 has 4 divisors (see below), whose sum is σ = 9077232. Its totient is φ = 4538612.

The previous prime is 6807919. The next prime is 6807923. The reversal of 6807921 is 1297086.

6807921 is digitally balanced in base 3, 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 an interprime number because it is at equal distance from previous prime (6807919) and next prime (6807923).

It is a cyclic number.

It is not a de Polignac number, because 6807921 - 2¹ = 6807919 is a prime.

It is a D-number.

6807921 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6807923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1134651 + ... + 1134656.

It is an arithmetic number, because the mean of its divisors is an integer number (2269308).

Almost surely, 2^6807921 is an apocalyptic number.

It is an amenable number.

6807921 is a deficient number, since it is larger than the sum of its proper divisors (2269311).

6807921 is a wasteful number, since it uses less digits than its factorization.

6807921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2269310.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 6807921 is about 2609.1993024681. The cubic root of 6807921 is about 189.5271807722.

The spelling of 6807921 in words is "six million, eight hundred seven thousand, nine hundred twenty-one".