811009 has 4 divisors (see below), whose sum is σ = 813316. Its totient is φ = 808704.

The previous prime is 810989. The next prime is 811037. The reversal of 811009 is 900118.

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 50625 + 760384 = 225^2 + 872^2 .

It is a cyclic number.

It is not a de Polignac number, because 811009 - 2⁷ = 810881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (811039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 504 + ... + 1369.

It is an arithmetic number, because the mean of its divisors is an integer number (203329).

It is a Proth number, since it is equal to 99 ⋅ 2¹³ + 1 and 99 < 2¹³.

2⁸¹¹⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

811009 is a deficient number, since it is larger than the sum of its proper divisors (2307).

811009 is a wasteful number, since it uses less digits than its factorization.

811009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2306.

The product of its (nonzero) digits is 72, while the sum is 19.

The square root of 811009 is about 900.5603810961. The cubic root of 811009 is about 93.2556652611.

The spelling of 811009 in words is "eight hundred eleven thousand, nine".