856991982855 has 16 divisors (see below), whose sum is σ = 1394427634560. Its totient is φ = 449315570208.

The previous prime is 856991982811. The next prime is 856991982877. The reversal of 856991982855 is 558289199658.

856991982855 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 856991982855 - 2³⁵ = 822632244487 is a prime.

It is a super-2 number, since 2×856991982855² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 484175377 + ... + 484177146.

It is an arithmetic number, because the mean of its divisors is an integer number (87151727160).

Almost surely, 2^856991982855 is an apocalyptic number.

856991982855 is a deficient number, since it is larger than the sum of its proper divisors (537435651705).

856991982855 is a wasteful number, since it uses less digits than its factorization.

856991982855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 968352590.

The product of its digits is 559872000, while the sum is 75.

The spelling of 856991982855 in words is "eight hundred fifty-six billion, nine hundred ninety-one million, nine hundred eighty-two thousand, eight hundred fifty-five".