813939 has 20 divisors (see below), whose sum is σ = 1277256. Its totient is φ = 460992.

The previous prime is 813931. The next prime is 813961. The reversal of 813939 is 939318.

It is not a de Polignac number, because 813939 - 2³ = 813931 is a prime.

It is a plaindrome in base 15.

It is a nialpdrome in base 7.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 813939.

It is not an unprimeable number, because it can be changed into a prime (813931) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 7147 + ... + 7259.

2⁸¹³⁹³⁹ is an apocalyptic number.

813939 is a deficient number, since it is larger than the sum of its proper divisors (463317).

813939 is an equidigital number, since it uses as much as digits as its factorization.

813939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 123 counting only the distinct ones).

The product of its digits is 5832, while the sum is 33.

The square root of 813939 is about 902.1856793366. The cubic root of 813939 is about 93.3678344671.

The spelling of 813939 in words is "eight hundred thirteen thousand, nine hundred thirty-nine".