856171031 has 4 divisors (see below), whose sum is σ = 885694200. Its totient is φ = 826647864.

The previous prime is 856171013. The next prime is 856171097. The reversal of 856171031 is 130171658.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-856171031 is a prime.

It is a super-2 number, since 2×856171031² = 1466057668647205922, 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 (856171931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14761541 + ... + 14761598.

It is an arithmetic number, because the mean of its divisors is an integer number (221423550).

Almost surely, 2^856171031 is an apocalyptic number.

856171031 is a deficient number, since it is larger than the sum of its proper divisors (29523169).

856171031 is a wasteful number, since it uses less digits than its factorization.

856171031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29523168.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 856171031 is about 29260.4003902886. The cubic root of 856171031 is about 949.5551124661. Note that the first 3 decimals are identical.

The spelling of 856171031 in words is "eight hundred fifty-six million, one hundred seventy-one thousand, thirty-one".