856917619638 has 8 divisors (see below), whose sum is σ = 1713835239288. Its totient is φ = 285639206544.

The previous prime is 856917619633. The next prime is 856917619681. The reversal of 856917619638 is 836916719658.

It is a sphenic number, since it is the product of 3 distinct primes.

856917619638 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856917619633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71409801631 + ... + 71409801642.

It is an arithmetic number, because the mean of its divisors is an integer number (214229404911).

Almost surely, 2^856917619638 is an apocalyptic number.

856917619638 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

856917619638 is a wasteful number, since it uses less digits than its factorization.

856917619638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142819603278.

The product of its digits is 117573120, while the sum is 69.

The spelling of 856917619638 in words is "eight hundred fifty-six billion, nine hundred seventeen million, six hundred nineteen thousand, six hundred thirty-eight".