2645809 has 2 divisors, whose sum is σ = 2645810. Its totient is φ = 2645808.

The previous prime is 2645779. The next prime is 2645827. The reversal of 2645809 is 9085462.

It is a happy number.

2645809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2640625 + 5184 = 1625^2 + 72^2 .

It is a cyclic number.

It is not a de Polignac number, because 2645809 - 2⁵ = 2645777 is a prime.

It is not a weakly prime, because it can be changed into another prime (2645849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1322904 + 1322905.

It is an arithmetic number, because the mean of its divisors is an integer number (1322905).

2^2645809 is an apocalyptic number.

It is an amenable number.

2645809 is a deficient number, since it is larger than the sum of its proper divisors (1).

2645809 is an equidigital number, since it uses as much as digits as its factorization.

2645809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 2645809 is about 1626.5942948381. The cubic root of 2645809 is about 138.3097606645.

The spelling of 2645809 in words is "two million, six hundred forty-five thousand, eight hundred nine".