809042905 has 12 divisors (see below), whose sum is σ = 1067135076. Its totient is φ = 588394400.

The previous prime is 809042891. The next prime is 809043043. The reversal of 809042905 is 509240908.

It can be written as a sum of positive squares in 2 ways, for example, as 161696656 + 647346249 = 12716^2 + 25443^2 .

It is not a de Polignac number, because 809042905 - 2¹⁹ = 808518617 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 668026 + ... + 669235.

It is an arithmetic number, because the mean of its divisors is an integer number (88927923).

Almost surely, 2^809042905 is an apocalyptic number.

It is an amenable number.

809042905 is a deficient number, since it is larger than the sum of its proper divisors (258092171).

809042905 is a wasteful number, since it uses less digits than its factorization.

809042905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1337288 (or 1337277 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 809042905 is about 28443.6795263904. The cubic root of 809042905 is about 931.8024568738.

The spelling of 809042905 in words is "eight hundred nine million, forty-two thousand, nine hundred five".