811993856 has 36 divisors (see below), whose sum is σ = 1625286600. Its totient is φ = 404877312.

The previous prime is 811993841. The next prime is 811993859. The reversal of 811993856 is 658399118.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (811993859) 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, 92840 + ... + 101208.

It is an arithmetic number, because the mean of its divisors is an integer number (45146850).

Almost surely, 2^811993856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 811993856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (812643300).

811993856 is an abundant number, since it is smaller than the sum of its proper divisors (813292744).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

811993856 is an equidigital number, since it uses as much as digits as its factorization.

811993856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8764 (or 8750 counting only the distinct ones).

The product of its digits is 466560, while the sum is 50.

The square root of 811993856 is about 28495.5058912805. The cubic root of 811993856 is about 932.9339860709.

The spelling of 811993856 in words is "eight hundred eleven million, nine hundred ninety-three thousand, eight hundred fifty-six".