809856985 has 16 divisors (see below), whose sum is σ = 1112544000. Its totient is φ = 554389056.

The previous prime is 809856919. The next prime is 809857001. The reversal of 809856985 is 589658908.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 809856985 - 2⁷ = 809856857 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1651 + ... + 40279.

It is an arithmetic number, because the mean of its divisors is an integer number (69534000).

Almost surely, 2^809856985 is an apocalyptic number.

It is an amenable number.

809856985 is a deficient number, since it is larger than the sum of its proper divisors (302687015).

809856985 is a wasteful number, since it uses less digits than its factorization.

809856985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39240.

The product of its (nonzero) digits is 6220800, while the sum is 58.

The square root of 809856985 is about 28457.9863131600. The cubic root of 809856985 is about 932.1148867228.

The spelling of 809856985 in words is "eight hundred nine million, eight hundred fifty-six thousand, nine hundred eighty-five".