813864 has 16 divisors (see below), whose sum is σ = 2034720. Its totient is φ = 271280.

The previous prime is 813863. The next prime is 813871. The reversal of 813864 is 468318.

It is a happy number.

It is a super-2 number, since 2×813864² = 1324749220992, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (813863) 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, 16932 + ... + 16979.

It is an arithmetic number, because the mean of its divisors is an integer number (127170).

2⁸¹³⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

813864 is an abundant number, since it is smaller than the sum of its proper divisors (1220856).

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

813864 is a wasteful number, since it uses less digits than its factorization.

813864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33920 (or 33916 counting only the distinct ones).

The product of its digits is 4608, while the sum is 30.

The square root of 813864 is about 902.1441126561. The cubic root of 813864 is about 93.3649666017.

The spelling of 813864 in words is "eight hundred thirteen thousand, eight hundred sixty-four".