856872889840 has 40 divisors (see below), whose sum is σ = 2173341241008. Its totient is φ = 311590141440.

The previous prime is 856872889819. The next prime is 856872889879. The reversal of 856872889840 is 48988278658.

856872889840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×856872889840² (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 7 ways as a sum of consecutive naturals, for example, 486858717 + ... + 486860476.

Almost surely, 2^856872889840 is an apocalyptic number.

856872889840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

856872889840 is an abundant number, since it is smaller than the sum of its proper divisors (1316468351168).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

856872889840 is a wasteful number, since it uses less digits than its factorization.

856872889840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 973719217 (or 973719211 counting only the distinct ones).

The product of its (nonzero) digits is 495452160, while the sum is 73.

It can be divided in two parts, 8568728 and 89840, that added together give a palindrome (8658568).

The spelling of 856872889840 in words is "eight hundred fifty-six billion, eight hundred seventy-two million, eight hundred eighty-nine thousand, eight hundred forty".