857085840 has 320 divisors, whose sum is σ = 3217294080. Its totient is φ = 208465920.

The previous prime is 857085809. The next prime is 857085841. The reversal of 857085840 is 48580758.

It is a super-2 number, since 2×857085840² = 1469192274257011200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (857085841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3678364 + ... + 3678596.

It is an arithmetic number, because the mean of its divisors is an integer number (10054044).

Almost surely, 2^857085840 is an apocalyptic number.

857085840 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 857085840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1608647040).

857085840 is an abundant number, since it is smaller than the sum of its proper divisors (2360208240).

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

857085840 is a wasteful number, since it uses less digits than its factorization.

857085840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399 (or 387 counting only the distinct ones).

The product of its (nonzero) digits is 358400, while the sum is 45.

The square root of 857085840 is about 29276.0284191692. The cubic root of 857085840 is about 949.8931883606.

The spelling of 857085840 in words is "eight hundred fifty-seven million, eighty-five thousand, eight hundred forty".