856111071921 has 32 divisors (see below), whose sum is σ = 1374114816000. Its totient is φ = 473425459920.

The previous prime is 856111071901. The next prime is 856111071967. The reversal of 856111071921 is 129170111658.

It is not a de Polignac number, because 856111071921 - 2¹⁴ = 856111055537 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (856111071901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13387191 + ... + 13450988.

It is an arithmetic number, because the mean of its divisors is an integer number (42941088000).

Almost surely, 2^856111071921 is an apocalyptic number.

It is an amenable number.

856111071921 is a deficient number, since it is larger than the sum of its proper divisors (518003744079).

856111071921 is a wasteful number, since it uses less digits than its factorization.

856111071921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26838234 (or 26838220 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 42.

The spelling of 856111071921 in words is "eight hundred fifty-six billion, one hundred eleven million, seventy-one thousand, nine hundred twenty-one".