809597813 has 4 divisors (see below), whose sum is σ = 820688268. Its totient is φ = 798507360.

The previous prime is 809597791. The next prime is 809597821. The reversal of 809597813 is 318795908.

809597813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 485849764 + 323748049 = 22042^2 + 17993^2 .

It is a cyclic number.

It is not a de Polignac number, because 809597813 - 2²⁴ = 792820597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (809597213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5545118 + ... + 5545263.

It is an arithmetic number, because the mean of its divisors is an integer number (205172067).

Almost surely, 2^809597813 is an apocalyptic number.

It is an amenable number.

809597813 is a deficient number, since it is larger than the sum of its proper divisors (11090455).

809597813 is a wasteful number, since it uses less digits than its factorization.

809597813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11090454.

The product of its (nonzero) digits is 544320, while the sum is 50.

The square root of 809597813 is about 28453.4323588561. The cubic root of 809597813 is about 932.0154437106.

The spelling of 809597813 in words is "eight hundred nine million, five hundred ninety-seven thousand, eight hundred thirteen".