813235691 has 4 divisors (see below), whose sum is σ = 835215072. Its totient is φ = 791256312.

The previous prime is 813235649. The next prime is 813235693. The reversal of 813235691 is 196532318.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 196532318 = 2 ⋅98266159.

It is a cyclic number.

It is not a de Polignac number, because 813235691 - 2⁶ = 813235627 is a prime.

It is a super-2 number, since 2×813235691² = 1322704578232494962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (813235693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10989635 + ... + 10989708.

It is an arithmetic number, because the mean of its divisors is an integer number (208803768).

Almost surely, 2^813235691 is an apocalyptic number.

813235691 is a deficient number, since it is larger than the sum of its proper divisors (21979381).

813235691 is a wasteful number, since it uses less digits than its factorization.

813235691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21979380.

The product of its digits is 38880, while the sum is 38.

The square root of 813235691 is about 28517.2875813953. The cubic root of 813235691 is about 933.4093426901.

The spelling of 813235691 in words is "eight hundred thirteen million, two hundred thirty-five thousand, six hundred ninety-one".