811861056 has 98 divisors (see below), whose sum is σ = 2415589022. Its totient is φ = 270604800.

The previous prime is 811861021. The next prime is 811861069. The reversal of 811861056 is 650168118.

It can be written as a sum of positive squares in only one way, i.e., 717382656 + 94478400 = 26784^2 + 9720^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 811861056.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 37956 + ... + 55356.

Almost surely, 2^811861056 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 811861056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1207794511).

811861056 is an abundant number, since it is smaller than the sum of its proper divisors (1603727966).

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

811861056 is an equidigital number, since it uses as much as digits as its factorization.

811861056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17431 (or 17406 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 811861056 is about 28493.1756039933. The cubic root of 811861056 is about 932.8831234578.

The spelling of 811861056 in words is "eight hundred eleven million, eight hundred sixty-one thousand, fifty-six".