856789840 has 20 divisors (see below), whose sum is σ = 1992036564. Its totient is φ = 342715904.

The previous prime is 856789823. The next prime is 856789847. The reversal of 856789840 is 48987658.

856789840 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 532501776 + 324288064 = 23076^2 + 18008^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856789847) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5354857 + ... + 5355016.

Almost surely, 2^856789840 is an apocalyptic number.

856789840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

856789840 is an abundant number, since it is smaller than the sum of its proper divisors (1135246724).

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

856789840 is a wasteful number, since it uses less digits than its factorization.

856789840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10709886 (or 10709880 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 55.

The square root of 856789840 is about 29270.9726521002. The cubic root of 856789840 is about 949.7838252355.

The spelling of 856789840 in words is "eight hundred fifty-six million, seven hundred eighty-nine thousand, eight hundred forty".