811609 has 4 divisors (see below), whose sum is σ = 814516. Its totient is φ = 808704.

The previous prime is 811607. The next prime is 811619. The reversal of 811609 is 906118.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 176400 + 635209 = 420^2 + 797^2 .

It is a cyclic number.

It is not a de Polignac number, because 811609 - 2¹ = 811607 is a prime.

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 (811607) 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, 984 + ... + 1609.

It is an arithmetic number, because the mean of its divisors is an integer number (203629).

2⁸¹¹⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

811609 is a deficient number, since it is larger than the sum of its proper divisors (2907).

811609 is a wasteful number, since it uses less digits than its factorization.

811609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2906.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 811609 is about 900.8934454196. The cubic root of 811609 is about 93.2786570349.

The spelling of 811609 in words is "eight hundred eleven thousand, six hundred nine".