8640865439 has 4 divisors (see below), whose sum is σ = 8729946624. Its totient is φ = 8551784256.

The previous prime is 8640865421. The next prime is 8640865483. The reversal of 8640865439 is 9345680468.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 8640865439 - 2⁸ = 8640865183 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 (8640865939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44540447 + ... + 44540640.

It is an arithmetic number, because the mean of its divisors is an integer number (2182486656).

Almost surely, 2^8640865439 is an apocalyptic number.

8640865439 is a deficient number, since it is larger than the sum of its proper divisors (89081185).

8640865439 is an equidigital number, since it uses as much as digits as its factorization.

8640865439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89081184.

The product of its (nonzero) digits is 4976640, while the sum is 53.

The square root of 8640865439 is about 92956.2555130100. The cubic root of 8640865439 is about 2052.0396466817.

The spelling of 8640865439 in words is "eight billion, six hundred forty million, eight hundred sixty-five thousand, four hundred thirty-nine".