856444257 has 6 divisors (see below), whose sum is σ = 1237086162. Its totient is φ = 570962832.

The previous prime is 856444243. The next prime is 856444273. The reversal of 856444257 is 752444658.

It can be written as a sum of positive squares in only one way, i.e., 628555041 + 227889216 = 25071^2 + 15096^2 .

It is not a de Polignac number, because 856444257 - 2²² = 852249953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (856844257) 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 5 ways as a sum of consecutive naturals, for example, 47580228 + ... + 47580245.

It is an arithmetic number, because the mean of its divisors is an integer number (206181027).

Almost surely, 2^856444257 is an apocalyptic number.

It is an amenable number.

856444257 is a deficient number, since it is larger than the sum of its proper divisors (380641905).

856444257 is a wasteful number, since it uses less digits than its factorization.

856444257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95160479 (or 95160476 counting only the distinct ones).

The product of its digits is 1075200, while the sum is 45.

The square root of 856444257 is about 29265.0688876688. The cubic root of 856444257 is about 949.6561108034.

The spelling of 856444257 in words is "eight hundred fifty-six million, four hundred forty-four thousand, two hundred fifty-seven".