856149840 has 480 divisors, whose sum is σ = 3607269120. Its totient is φ = 177168384.

The previous prime is 856149821. The next prime is 856149841. The reversal of 856149840 is 48941658.

856149840 is a `hidden beast` number, since 8 + 561 + 4 + 9 + 84 + 0 = 666.

856149840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 (856149841) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4782871 + ... + 4783049.

It is an arithmetic number, because the mean of its divisors is an integer number (7515144).

Almost surely, 2^856149840 is an apocalyptic number.

856149840 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 856149840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1803634560).

856149840 is an abundant number, since it is smaller than the sum of its proper divisors (2751119280).

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

856149840 is a wasteful number, since it uses less digits than its factorization.

856149840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291 (or 282 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The square root of 856149840 is about 29260.0382774869. The cubic root of 856149840 is about 949.5472782883.

The spelling of 856149840 in words is "eight hundred fifty-six million, one hundred forty-nine thousand, eight hundred forty".