856986816 has 224 divisors, whose sum is σ = 2723725312. Its totient is φ = 232657920.

The previous prime is 856986791. The next prime is 856986817. The reversal of 856986816 is 618689658.

It is a tau number, because it is divible by the number of its divisors (224).

It is not an unprimeable number, because it can be changed into a prime (856986817) 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 31 ways as a sum of consecutive naturals, for example, 2791335 + ... + 2791641.

It is an arithmetic number, because the mean of its divisors is an integer number (12159488).

Almost surely, 2^856986816 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 856986816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1361862656).

856986816 is an abundant number, since it is smaller than the sum of its proper divisors (1866738496).

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

856986816 is a wasteful number, since it uses less digits than its factorization.

856986816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427 (or 417 counting only the distinct ones).

The product of its digits is 4976640, while the sum is 57.

The square root of 856986816 is about 29274.3371573124. The cubic root of 856986816 is about 949.8566047648.

The spelling of 856986816 in words is "eight hundred fifty-six million, nine hundred eighty-six thousand, eight hundred sixteen".