810909 has 12 divisors (see below), whose sum is σ = 1277952. Its totient is φ = 491400.

The previous prime is 810907. The next prime is 810913. The reversal of 810909 is 909018.

It is not a de Polignac number, because 810909 - 2¹ = 810907 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is an alternating number because its digits alternate between even and odd.

810909 is a modest number, since divided by 909 gives 81 as remainder.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (810907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3997 + ... + 4194.

It is an arithmetic number, because the mean of its divisors is an integer number (106496).

2⁸¹⁰⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

810909 is a deficient number, since it is larger than the sum of its proper divisors (467043).

810909 is a wasteful number, since it uses less digits than its factorization.

810909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8208 (or 8205 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 810909 is about 900.5048583989. The cubic root of 810909 is about 93.2518321964.

The spelling of 810909 in words is "eight hundred ten thousand, nine hundred nine".