856628257 has 16 divisors (see below), whose sum is σ = 885297600. Its totient is φ = 828555520.

The previous prime is 856628207. The next prime is 856628263. The reversal of 856628257 is 752826658.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-856628257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 856628257.

It is not an unprimeable number, because it can be changed into a prime (856628207) 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 15 ways as a sum of consecutive naturals, for example, 1058469 + ... + 1059277.

It is an arithmetic number, because the mean of its divisors is an integer number (55331100).

Almost surely, 2^856628257 is an apocalyptic number.

It is an amenable number.

856628257 is a deficient number, since it is larger than the sum of its proper divisors (28669343).

856628257 is a wasteful number, since it uses less digits than its factorization.

856628257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1136.

The product of its digits is 1612800, while the sum is 49.

The square root of 856628257 is about 29268.2123984366. The cubic root of 856628257 is about 949.7241145335.

The spelling of 856628257 in words is "eight hundred fifty-six million, six hundred twenty-eight thousand, two hundred fifty-seven".