85721665239 has 48 divisors (see below), whose sum is σ = 146439820800. Its totient is φ = 47278099008.

The previous prime is 85721665223. The next prime is 85721665273. The reversal of 85721665239 is 93256612758.

85721665239 is a `hidden beast` number, since 8 + 57 + 2 + 1 + 66 + 523 + 9 = 666.

It is not a de Polignac number, because 85721665239 - 2⁴ = 85721665223 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85721645239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6678582 + ... + 6691404.

It is an arithmetic number, because the mean of its divisors is an integer number (3050829600).

Almost surely, 2^85721665239 is an apocalyptic number.

85721665239 is a deficient number, since it is larger than the sum of its proper divisors (60718155561).

85721665239 is a wasteful number, since it uses less digits than its factorization.

85721665239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16524 (or 16521 counting only the distinct ones).

The product of its digits is 5443200, while the sum is 54.

The spelling of 85721665239 in words is "eighty-five billion, seven hundred twenty-one million, six hundred sixty-five thousand, two hundred thirty-nine".