809642813 has 16 divisors (see below), whose sum is σ = 941844480. Its totient is φ = 681609600.

The previous prime is 809642773. The next prime is 809642923. The reversal of 809642813 is 318246908.

It is not a de Polignac number, because 809642813 - 2⁸ = 809642557 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 (809642513) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 549668 + ... + 551138.

It is an arithmetic number, because the mean of its divisors is an integer number (58865280).

Almost surely, 2^809642813 is an apocalyptic number.

It is an amenable number.

809642813 is a deficient number, since it is larger than the sum of its proper divisors (132201667).

809642813 is a wasteful number, since it uses less digits than its factorization.

809642813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2828.

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 809642813 is about 28454.2231136259. The cubic root of 809642813 is about 932.0327115101.

The spelling of 809642813 in words is "eight hundred nine million, six hundred forty-two thousand, eight hundred thirteen".