856861824 has 384 divisors, whose sum is σ = 2969326080. Its totient is φ = 216760320.

The previous prime is 856861813. The next prime is 856861843. The reversal of 856861824 is 428168658.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 7582792 + ... + 7582904.

It is an arithmetic number, because the mean of its divisors is an integer number (7732620).

Almost surely, 2^856861824 is an apocalyptic number.

856861824 is a gapful number since it is divisible by the number (84) 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 856861824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1484663040).

856861824 is an abundant number, since it is smaller than the sum of its proper divisors (2112464256).

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

856861824 is a wasteful number, since it uses less digits than its factorization.

856861824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188 (or 169 counting only the distinct ones).

The product of its digits is 737280, while the sum is 48.

The square root of 856861824 is about 29272.2022403508. The cubic root of 856861824 is about 949.8104234829.

The spelling of 856861824 in words is "eight hundred fifty-six million, eight hundred sixty-one thousand, eight hundred twenty-four".