809231899691 has 2 divisors, whose sum is σ = 809231899692. Its totient is φ = 809231899690.

The previous prime is 809231899669. The next prime is 809231899771. The reversal of 809231899691 is 196998132908.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 809231899691 - 2³⁸ = 534353992747 is a prime.

It is not a weakly prime, because it can be changed into another prime (809231899601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 404615949845 + 404615949846.

It is an arithmetic number, because the mean of its divisors is an integer number (404615949846).

Almost surely, 2^809231899691 is an apocalyptic number.

809231899691 is a deficient number, since it is larger than the sum of its proper divisors (1).

809231899691 is an equidigital number, since it uses as much as digits as its factorization.

809231899691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15116544, while the sum is 65.

The spelling of 809231899691 in words is "eight hundred nine billion, two hundred thirty-one million, eight hundred ninety-nine thousand, six hundred ninety-one".