856639808136 has 192 divisors, whose sum is σ = 2714873616000. Its totient is φ = 243916831872.

The previous prime is 856639808131. The next prime is 856639808153. The reversal of 856639808136 is 631808936658.

856639808136 is a `hidden beast` number, since 8 + 566 + 39 + 8 + 0 + 8 + 1 + 36 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (856639808131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7176735 + ... + 7295121.

It is an arithmetic number, because the mean of its divisors is an integer number (14139966750).

Almost surely, 2^856639808136 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 856639808136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1357436808000).

856639808136 is an abundant number, since it is smaller than the sum of its proper divisors (1858233807864).

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

856639808136 is a wasteful number, since it uses less digits than its factorization.

856639808136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118713 (or 118692 counting only the distinct ones).

The product of its (nonzero) digits is 44789760, while the sum is 63.

The spelling of 856639808136 in words is "eight hundred fifty-six billion, six hundred thirty-nine million, eight hundred eight thousand, one hundred thirty-six".