813904 has 60 divisors (see below), whose sum is σ = 1996896. Its totient is φ = 314496.

The previous prime is 813893. The next prime is 813907. The reversal of 813904 is 409318.

It is a zygodrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (813907) by changing a digit.

813904 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18907 + ... + 18949.

2⁸¹³⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 813904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (998448).

813904 is an abundant number, since it is smaller than the sum of its proper divisors (1182992).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

813904 is a wasteful number, since it uses less digits than its factorization.

813904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84 (or 65 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 813904 is about 902.1662817907. The cubic root of 813904 is about 93.3664961518.

The spelling of 813904 in words is "eight hundred thirteen thousand, nine hundred four".