856064440 has 128 divisors (see below), whose sum is σ = 2410560000. Its totient is φ = 265812480.

The previous prime is 856064401. The next prime is 856064441. The reversal of 856064440 is 44460658.

It is a self number, because there is not a number n which added to its sum of digits gives 856064440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856064441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1536642 + ... + 1537198.

It is an arithmetic number, because the mean of its divisors is an integer number (18832500).

Almost surely, 2^856064440 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 856064440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1205280000).

856064440 is an abundant number, since it is smaller than the sum of its proper divisors (1554495560).

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

856064440 is a wasteful number, since it uses less digits than its factorization.

856064440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1085 (or 1081 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 37.

The square root of 856064440 is about 29258.5789128590. The cubic root of 856064440 is about 949.5157051414.

The spelling of 856064440 in words is "eight hundred fifty-six million, sixty-four thousand, four hundred forty".