856961728 has 56 divisors (see below), whose sum is σ = 1954877472. Its totient is φ = 365113344.

The previous prime is 856961723. The next prime is 856961741. The reversal of 856961728 is 827169658.

It is a tau number, because it is divible by the number of its divisors (56).

It is not an unprimeable number, because it can be changed into a prime (856961723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71976 + ... + 83032.

Almost surely, 2^856961728 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 856961728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (977438736).

856961728 is an abundant number, since it is smaller than the sum of its proper divisors (1097915744).

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

856961728 is a wasteful number, since it uses less digits than its factorization.

856961728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11249 (or 11239 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 52.

The square root of 856961728 is about 29273.9086560029. The cubic root of 856961728 is about 949.8473357638.

The spelling of 856961728 in words is "eight hundred fifty-six million, nine hundred sixty-one thousand, seven hundred twenty-eight".