856909694256 has 640 divisors, whose sum is σ = 2988665856000. Its totient is φ = 209139840000.

The previous prime is 856909694239. The next prime is 856909694261. The reversal of 856909694256 is 652496909658.

It is a super-2 number, since 2×856909694256² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

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 127 ways as a sum of consecutive naturals, for example, 450766906 + ... + 450768806.

It is an arithmetic number, because the mean of its divisors is an integer number (4669790400).

Almost surely, 2^856909694256 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 856909694256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1494332928000).

856909694256 is an abundant number, since it is smaller than the sum of its proper divisors (2131756161744).

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

856909694256 is a wasteful number, since it uses less digits than its factorization.

856909694256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2094 (or 2074 counting only the distinct ones).

The product of its (nonzero) digits is 251942400, while the sum is 69.

The spelling of 856909694256 in words is "eight hundred fifty-six billion, nine hundred nine million, six hundred ninety-four thousand, two hundred fifty-six".