856975831 has 4 divisors (see below), whose sum is σ = 907386192. Its totient is φ = 806565472.

The previous prime is 856975817. The next prime is 856975859. The reversal of 856975831 is 138579658.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 856975831 - 2¹⁵ = 856943063 is a prime.

It is a super-2 number, since 2×856975831² = 1468815149836281122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856970831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25205155 + ... + 25205188.

It is an arithmetic number, because the mean of its divisors is an integer number (226846548).

Almost surely, 2^856975831 is an apocalyptic number.

856975831 is a deficient number, since it is larger than the sum of its proper divisors (50410361).

856975831 is a wasteful number, since it uses less digits than its factorization.

856975831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50410360.

The product of its digits is 1814400, while the sum is 52.

The square root of 856975831 is about 29274.1495350420. The cubic root of 856975831 is about 949.8525462740.

The spelling of 856975831 in words is "eight hundred fifty-six million, nine hundred seventy-five thousand, eight hundred thirty-one".