809609 has 4 divisors (see below), whose sum is σ = 852240. Its totient is φ = 766980.

The previous prime is 809603. The next prime is 809629. The reversal of 809609 is 906908.

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 a de Polignac number, because none of the positive numbers 2^k-809609 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (809603) 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, 21287 + ... + 21324.

It is an arithmetic number, because the mean of its divisors is an integer number (213060).

2⁸⁰⁹⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

809609 is a deficient number, since it is larger than the sum of its proper divisors (42631).

809609 is a wasteful number, since it uses less digits than its factorization.

809609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42630.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 809609 is about 899.7827515573. The cubic root of 809609 is about 93.2019736545.

The spelling of 809609 in words is "eight hundred nine thousand, six hundred nine".