6845809 has 2 divisors, whose sum is σ = 6845810. Its totient is φ = 6845808.

The previous prime is 6845807. The next prime is 6845819. The reversal of 6845809 is 9085486.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5895184 + 950625 = 2428^2 + 975^2 .

It is a cyclic number.

It is not a de Polignac number, because 6845809 - 2¹ = 6845807 is a prime.

Together with 6845807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (6845803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3422904 + 3422905.

It is an arithmetic number, because the mean of its divisors is an integer number (3422905).

Almost surely, 2^6845809 is an apocalyptic number.

It is an amenable number.

6845809 is a deficient number, since it is larger than the sum of its proper divisors (1).

6845809 is an equidigital number, since it uses as much as digits as its factorization.

6845809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69120, while the sum is 40.

The square root of 6845809 is about 2616.4496937644. The cubic root of 6845809 is about 189.8781212815.

The spelling of 6845809 in words is "six million, eight hundred forty-five thousand, eight hundred nine".