809866 has 8 divisors (see below), whose sum is σ = 1219680. Its totient is φ = 403308.

The previous prime is 809843. The next prime is 809869. The reversal of 809866 is 668908.

809866 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (809869) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46 + ... + 1273.

It is an arithmetic number, because the mean of its divisors is an integer number (152460).

2⁸⁰⁹⁸⁶⁶ is an apocalyptic number.

809866 is a deficient number, since it is larger than the sum of its proper divisors (409814).

809866 is a wasteful number, since it uses less digits than its factorization.

809866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1628.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 809866 is about 899.9255524764. The cubic root of 809866 is about 93.2118345352.

The spelling of 809866 in words is "eight hundred nine thousand, eight hundred sixty-six".