813875989 has 4 divisors (see below), whose sum is σ = 815024620. Its totient is φ = 812727360.

The previous prime is 813875983. The next prime is 813876023. The reversal of 813875989 is 989578318.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 989578318 = 2 ⋅494789159.

It can be written as a sum of positive squares in 2 ways, for example, as 87142225 + 726733764 = 9335^2 + 26958^2 .

It is a cyclic number.

It is not a de Polignac number, because 813875989 - 2⁹ = 813875477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (813875983) 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, 573252 + ... + 574669.

It is an arithmetic number, because the mean of its divisors is an integer number (203756155).

Almost surely, 2^813875989 is an apocalyptic number.

It is an amenable number.

813875989 is a deficient number, since it is larger than the sum of its proper divisors (1148631).

813875989 is a wasteful number, since it uses less digits than its factorization.

813875989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1148630.

The product of its digits is 4354560, while the sum is 58.

The square root of 813875989 is about 28528.5118609436. The cubic root of 813875989 is about 933.6542505134.

The spelling of 813875989 in words is "eight hundred thirteen million, eight hundred seventy-five thousand, nine hundred eighty-nine".