813622809 has 4 divisors (see below), whose sum is σ = 1084830416. Its totient is φ = 542415204.

The previous prime is 813622801. The next prime is 813622829. The reversal of 813622809 is 908226318.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 813622809 - 2³ = 813622801 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (813622801) 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, 135603799 + ... + 135603804.

It is an arithmetic number, because the mean of its divisors is an integer number (271207604).

Almost surely, 2^813622809 is an apocalyptic number.

It is an amenable number.

813622809 is a deficient number, since it is larger than the sum of its proper divisors (271207607).

813622809 is a wasteful number, since it uses less digits than its factorization.

813622809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271207606.

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 813622809 is about 28524.0742005766. The cubic root of 813622809 is about 933.5574269589.

The spelling of 813622809 in words is "eight hundred thirteen million, six hundred twenty-two thousand, eight hundred nine".