857255221 has 4 divisors (see below), whose sum is σ = 857415744. Its totient is φ = 857094700.

The previous prime is 857255213. The next prime is 857255233. The reversal of 857255221 is 122552758.

857255221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 857255221 - 2³ = 857255213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (857255521) 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, 71965 + ... + 83026.

It is an arithmetic number, because the mean of its divisors is an integer number (214353936).

Almost surely, 2^857255221 is an apocalyptic number.

It is an amenable number.

857255221 is a deficient number, since it is larger than the sum of its proper divisors (160523).

857255221 is a wasteful number, since it uses less digits than its factorization.

857255221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160522.

The product of its digits is 56000, while the sum is 37.

The square root of 857255221 is about 29278.9211037565. The cubic root of 857255221 is about 949.9557582352.

It can be divided in two parts, 857255 and 221, that added together give a square (857476 = 926²).

The spelling of 857255221 in words is "eight hundred fifty-seven million, two hundred fifty-five thousand, two hundred twenty-one".