856842840 has 512 divisors, whose sum is σ = 3545856000. Its totient is φ = 179601408.

The previous prime is 856842817. The next prime is 856842841. The reversal of 856842840 is 48248658.

856842840 is a `hidden beast` number, since 8 + 568 + 4 + 2 + 84 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856842841) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 7582624 + ... + 7582736.

It is an arithmetic number, because the mean of its divisors is an integer number (6925500).

Almost surely, 2^856842840 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 856842840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1772928000).

856842840 is an abundant number, since it is smaller than the sum of its proper divisors (2689013160).

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

856842840 is a wasteful number, since it uses less digits than its factorization.

856842840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216 (or 206 counting only the distinct ones).

The product of its (nonzero) digits is 491520, while the sum is 45.

The square root of 856842840 is about 29271.8779718692. The cubic root of 856842840 is about 949.8034089975.

The spelling of 856842840 in words is "eight hundred fifty-six million, eight hundred forty-two thousand, eight hundred forty".