808642865 has 8 divisors (see below), whose sum is σ = 979979688. Its totient is φ = 640508800.

The previous prime is 808642853. The next prime is 808642921. The reversal of 808642865 is 568246808.

It can be written as a sum of positive squares in 4 ways, for example, as 48427681 + 760215184 = 6959^2 + 27572^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 808642865 - 2⁸ = 808642609 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 7 ways as a sum of consecutive naturals, for example, 800132 + ... + 801141.

It is an arithmetic number, because the mean of its divisors is an integer number (122497461).

Almost surely, 2^808642865 is an apocalyptic number.

It is an amenable number.

808642865 is a deficient number, since it is larger than the sum of its proper divisors (171336823).

808642865 is a wasteful number, since it uses less digits than its factorization.

808642865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1601379.

The product of its (nonzero) digits is 737280, while the sum is 47.

The square root of 808642865 is about 28436.6465146648. The cubic root of 808642865 is about 931.6488516251.

The spelling of 808642865 in words is "eight hundred eight million, six hundred forty-two thousand, eight hundred sixty-five".