856297728 has 432 divisors, whose sum is σ = 3053441664. Its totient is φ = 227082240.

The previous prime is 856297727. The next prime is 856297753. The reversal of 856297728 is 827792658.

It is a happy number.

856297728 is a `hidden beast` number, since 8 + 5 + 629 + 7 + 7 + 2 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856297723) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7577800 + ... + 7577912.

It is an arithmetic number, because the mean of its divisors is an integer number (7068152).

Almost surely, 2^856297728 is an apocalyptic number.

856297728 is a gapful number since it is divisible by the number (88) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 856297728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1526720832).

856297728 is an abundant number, since it is smaller than the sum of its proper divisors (2197143936).

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

856297728 is a wasteful number, since it uses less digits than its factorization.

856297728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182 (or 165 counting only the distinct ones).

The product of its digits is 3386880, while the sum is 54.

The square root of 856297728 is about 29262.5653010805. The cubic root of 856297728 is about 949.6019488442.

The spelling of 856297728 in words is "eight hundred fifty-six million, two hundred ninety-seven thousand, seven hundred twenty-eight".