2006809 has 4 divisors (see below), whose sum is σ = 2293504. Its totient is φ = 1720116.

The previous prime is 2006791. The next prime is 2006813. The reversal of 2006809 is 9086002.

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 a cyclic number.

It is not a de Polignac number, because 2006809 - 2⁹ = 2006297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2006869) 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, 143337 + ... + 143350.

It is an arithmetic number, because the mean of its divisors is an integer number (573376).

2^2006809 is an apocalyptic number.

It is an amenable number.

2006809 is a deficient number, since it is larger than the sum of its proper divisors (286695).

2006809 is an equidigital number, since it uses as much as digits as its factorization.

2006809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286694.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 2006809 is about 1416.6188619385. The cubic root of 2006809 is about 126.1349230776.

The spelling of 2006809 in words is "two million, six thousand, eight hundred nine".