809888081 has 4 divisors (see below), whose sum is σ = 809945700. Its totient is φ = 809830464.

The previous prime is 809888077. The next prime is 809888099. The reversal of 809888081 is 180888908.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 295324225 + 514563856 = 17185^2 + 22684^2 .

It is a cyclic number.

It is not a de Polignac number, because 809888081 - 2² = 809888077 is a prime.

It is a super-2 number, since 2×809888081² = 1311837407491725122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (809884081) 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 3 ways as a sum of consecutive naturals, for example, 7685 + ... + 40973.

It is an arithmetic number, because the mean of its divisors is an integer number (202486425).

Almost surely, 2^809888081 is an apocalyptic number.

It is an amenable number.

809888081 is a deficient number, since it is larger than the sum of its proper divisors (57619).

809888081 is a wasteful number, since it uses less digits than its factorization.

809888081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57618.

The product of its (nonzero) digits is 294912, while the sum is 50.

The square root of 809888081 is about 28458.5326571839. The cubic root of 809888081 is about 932.1268166784.

The spelling of 809888081 in words is "eight hundred nine million, eight hundred eighty-eight thousand, eighty-one".