811856556 has 72 divisors (see below), whose sum is σ = 2483339040. Its totient is φ = 218313216.

The previous prime is 811856543. The next prime is 811856557. The reversal of 811856556 is 655658118.

811856556 is a `hidden beast` number, since 8 + 11 + 85 + 6 + 556 = 666.

811856556 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×811856556² = 1318222135040362272, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (811856557) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 90471 + ... + 99038.

It is an arithmetic number, because the mean of its divisors is an integer number (34490820).

Almost surely, 2^811856556 is an apocalyptic number.

It is an amenable number.

811856556 is an abundant number, since it is smaller than the sum of its proper divisors (1671482484).

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

811856556 is a wasteful number, since it uses less digits than its factorization.

811856556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189543 (or 189538 counting only the distinct ones).

The product of its digits is 288000, while the sum is 45.

The square root of 811856556 is about 28493.0966376068. The cubic root of 811856556 is about 932.8813998534.

The spelling of 811856556 in words is "eight hundred eleven million, eight hundred fifty-six thousand, five hundred fifty-six".