809689 has 4 divisors (see below), whose sum is σ = 835840. Its totient is φ = 783540.

The previous prime is 809629. The next prime is 809701. The reversal of 809689 is 986908.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 809689 - 2⁹ = 809177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (809629) 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 3 ways as a sum of consecutive naturals, for example, 13029 + ... + 13090.

It is an arithmetic number, because the mean of its divisors is an integer number (208960).

2⁸⁰⁹⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

809689 is a deficient number, since it is larger than the sum of its proper divisors (26151).

809689 is a wasteful number, since it uses less digits than its factorization.

809689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26150.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 809689 is about 899.8272056345. The cubic root of 809689 is about 93.2050434130.

The spelling of 809689 in words is "eight hundred nine thousand, six hundred eighty-nine".