857391949856 has 96 divisors (see below), whose sum is σ = 1830017064960. Its totient is φ = 393070454784.

The previous prime is 857391949831. The next prime is 857391949859. The reversal of 857391949856 is 658949193758.

Its product of digits (587865600) is a multiple of the sum of its prime divisors (7290).

It is not an unprimeable number, because it can be changed into a prime (857391949859) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 239292641 + ... + 239296223.

It is an arithmetic number, because the mean of its divisors is an integer number (19062677760).

Almost surely, 2^857391949856 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 857391949856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (915008532480).

857391949856 is an abundant number, since it is smaller than the sum of its proper divisors (972625115104).

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

857391949856 is a wasteful number, since it uses less digits than its factorization.

857391949856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7298 (or 7290 counting only the distinct ones).

The product of its digits is 587865600, while the sum is 74.

The spelling of 857391949856 in words is "eight hundred fifty-seven billion, three hundred ninety-one million, nine hundred forty-nine thousand, eight hundred fifty-six".