811976985 has 12 divisors (see below), whose sum is σ = 1407426852. Its totient is φ = 433054368.

The previous prime is 811976983. The next prime is 811976999. The reversal of 811976985 is 589679118.

It can be written as a sum of positive squares in 2 ways, for example, as 206669376 + 605307609 = 14376^2 + 24603^2 .

It is not a de Polignac number, because 811976985 - 2¹ = 811976983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (811976983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9021922 + ... + 9022011.

It is an arithmetic number, because the mean of its divisors is an integer number (117285571).

Almost surely, 2^811976985 is an apocalyptic number.

It is an amenable number.

811976985 is a deficient number, since it is larger than the sum of its proper divisors (595449867).

811976985 is a wasteful number, since it uses less digits than its factorization.

811976985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18043944 (or 18043941 counting only the distinct ones).

The product of its digits is 1088640, while the sum is 54.

The square root of 811976985 is about 28495.2098606064. The cubic root of 811976985 is about 932.9275247584.

It can be divided in two parts, 81 and 1976985, that added together give a triangular number (1977066 = T₁₉₈₈).

The spelling of 811976985 in words is "eight hundred eleven million, nine hundred seventy-six thousand, nine hundred eighty-five".