813691809 has 24 divisors (see below), whose sum is σ = 1347016320. Its totient is φ = 463658688.

The previous prime is 813691807. The next prime is 813691817. The reversal of 813691809 is 908196318.

It is not a de Polignac number, because 813691809 - 2¹ = 813691807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (813691807) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4629 + ... + 40605.

It is an arithmetic number, because the mean of its divisors is an integer number (56125680).

Almost surely, 2^813691809 is an apocalyptic number.

It is an amenable number.

813691809 is a deficient number, since it is larger than the sum of its proper divisors (533324511).

813691809 is a wasteful number, since it uses less digits than its factorization.

813691809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36349 (or 36346 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 813691809 is about 28525.2836795710. The cubic root of 813691809 is about 933.5838165999.

The spelling of 813691809 in words is "eight hundred thirteen million, six hundred ninety-one thousand, eight hundred nine".