856899540 has 192 divisors, whose sum is σ = 3152217600. Its totient is φ = 189084672.

The previous prime is 856899509. The next prime is 856899541. The reversal of 856899540 is 45998658.

It is a happy number.

856899540 is a `hidden beast` number, since 8 + 5 + 6 + 8 + 99 + 540 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856899541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 105712 + ... + 113528.

It is an arithmetic number, because the mean of its divisors is an integer number (16417800).

Almost surely, 2^856899540 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 856899540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1576108800).

856899540 is an abundant number, since it is smaller than the sum of its proper divisors (2295318060).

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

856899540 is a wasteful number, since it uses less digits than its factorization.

856899540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7871 (or 7863 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 54.

The square root of 856899540 is about 29272.8464622079. The cubic root of 856899540 is about 949.8243590337.

The spelling of 856899540 in words is "eight hundred fifty-six million, eight hundred ninety-nine thousand, five hundred forty".