809666001 has 12 divisors (see below), whose sum is σ = 1191584628. Its totient is φ = 529592544.

The previous prime is 809665973. The next prime is 809666003. The reversal of 809666001 is 100666908.

It can be written as a sum of positive squares in 2 ways, for example, as 732243600 + 77422401 = 27060^2 + 8799^2 .

It is not a de Polignac number, because 809666001 - 2⁷ = 809665873 is a prime.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (809666003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 848230 + ... + 849183.

It is an arithmetic number, because the mean of its divisors is an integer number (99298719).

Almost surely, 2^809666001 is an apocalyptic number.

It is an amenable number.

809666001 is a deficient number, since it is larger than the sum of its proper divisors (381918627).

809666001 is a wasteful number, since it uses less digits than its factorization.

809666001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1697472 (or 1697469 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 809666001 is about 28454.6305721933. The cubic root of 809666001 is about 932.0416091654.

The spelling of 809666001 in words is "eight hundred nine million, six hundred sixty-six thousand, one".