6857257840 has 20 divisors (see below), whose sum is σ = 15943124664. Its totient is φ = 2742903104.

The previous prime is 6857257829. The next prime is 6857257867. The reversal of 6857257840 is 487527586.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 42857782 + ... + 42857941.

Almost surely, 2^6857257840 is an apocalyptic number.

It is an amenable number.

6857257840 is an abundant number, since it is smaller than the sum of its proper divisors (9085866824).

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

6857257840 is a wasteful number, since it uses less digits than its factorization.

6857257840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85715736 (or 85715730 counting only the distinct ones).

The product of its (nonzero) digits is 3763200, while the sum is 52.

The square root of 6857257840 is about 82808.5613931313. The cubic root of 6857257840 is about 1899.8391221125.

The spelling of 6857257840 in words is "six billion, eight hundred fifty-seven million, two hundred fifty-seven thousand, eight hundred forty".