813989 has 4 divisors (see below), whose sum is σ = 888000. Its totient is φ = 739980.

The previous prime is 813971. The next prime is 813991. The reversal of 813989 is 989318.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 813989 - 2¹⁶ = 748453 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 13 and 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 813989.

It is not an unprimeable number, because it can be changed into a prime (813089) 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 3 ways as a sum of consecutive naturals, for example, 36989 + ... + 37010.

It is an arithmetic number, because the mean of its divisors is an integer number (222000).

2⁸¹³⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

813989 is a deficient number, since it is larger than the sum of its proper divisors (74011).

813989 is a wasteful number, since it uses less digits than its factorization.

813989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74010.

The product of its digits is 15552, while the sum is 38.

The square root of 813989 is about 902.2133893930. The cubic root of 813989 is about 93.3697462796.

It can be divided in two parts, 8139 and 89, that added together give a palindrome (8228).

The spelling of 813989 in words is "eight hundred thirteen thousand, nine hundred eighty-nine".