2805809 has 2 divisors, whose sum is σ = 2805810. Its totient is φ = 2805808.

The previous prime is 2805791. The next prime is 2805827. The reversal of 2805809 is 9085082.

It is a balanced prime because it is at equal distance from previous prime (2805791) and next prime (2805827).

It can be written as a sum of positive squares in only one way, i.e., 1682209 + 1123600 = 1297^2 + 1060^2 .

It is a cyclic number.

It is not a de Polignac number, because 2805809 - 2¹² = 2801713 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2805899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1402904 + 1402905.

It is an arithmetic number, because the mean of its divisors is an integer number (1402905).

2^2805809 is an apocalyptic number.

It is an amenable number.

2805809 is a deficient number, since it is larger than the sum of its proper divisors (1).

2805809 is an equidigital number, since it uses as much as digits as its factorization.

2805809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 2805809 is about 1675.0549244726. The cubic root of 2805809 is about 141.0433781663.

The spelling of 2805809 in words is "two million, eight hundred five thousand, eight hundred nine".