813909 has 8 divisors (see below), whose sum is σ = 1149120. Its totient is φ = 510656.

The previous prime is 813907. The next prime is 813931. The reversal of 813909 is 909318.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 813909 - 2¹ = 813907 is a prime.

It is a Curzon number.

It is a plaindrome in base 15.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 813909.

It is not an unprimeable number, because it can be changed into a prime (813907) 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 7 ways as a sum of consecutive naturals, for example, 7929 + ... + 8030.

It is an arithmetic number, because the mean of its divisors is an integer number (143640).

2⁸¹³⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

813909 is a deficient number, since it is larger than the sum of its proper divisors (335211).

813909 is a wasteful number, since it uses less digits than its factorization.

813909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15979.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 813909 is about 902.1690528942. The cubic root of 813909 is about 93.3666873421.

The spelling of 813909 in words is "eight hundred thirteen thousand, nine hundred nine".