856873840 has 80 divisors (see below), whose sum is σ = 2021120640. Its totient is φ = 337824000.

The previous prime is 856873793. The next prime is 856873907. The reversal of 856873840 is 48378658.

856873840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2790967 + ... + 2791273.

It is an arithmetic number, because the mean of its divisors is an integer number (25264008).

Almost surely, 2^856873840 is an apocalyptic number.

856873840 is a gapful number since it is divisible by the number (80) 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 856873840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1010560320).

856873840 is an abundant number, since it is smaller than the sum of its proper divisors (1164246800).

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

856873840 is a wasteful number, since it uses less digits than its factorization.

856873840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710 (or 704 counting only the distinct ones).

The product of its (nonzero) digits is 1290240, while the sum is 49.

The square root of 856873840 is about 29272.4074855486. The cubic root of 856873840 is about 949.8148632764.

The spelling of 856873840 in words is "eight hundred fifty-six million, eight hundred seventy-three thousand, eight hundred forty".