811309681 has 48 divisors (see below), whose sum is σ = 1055134080. Its totient is φ = 610122240.

The previous prime is 811309607. The next prime is 811309703. The reversal of 811309681 is 186903118.

811309681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 811309681 - 2²⁷ = 677091953 is a prime.

It is a super-2 number, since 2×811309681² = 1316446796968643522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 811309681.

It is not an unprimeable number, because it can be changed into a prime (811309181) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2085435 + ... + 2085823.

It is an arithmetic number, because the mean of its divisors is an integer number (21981960).

Almost surely, 2^811309681 is an apocalyptic number.

It is an amenable number.

811309681 is a deficient number, since it is larger than the sum of its proper divisors (243824399).

811309681 is a wasteful number, since it uses less digits than its factorization.

811309681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 506 (or 493 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 37.

The square root of 811309681 is about 28483.4983981954. The cubic root of 811309681 is about 932.6718866061.

The spelling of 811309681 in words is "eight hundred eleven million, three hundred nine thousand, six hundred eighty-one".