Is 857 a prime number? What are the divisors of 857?

## Parity of 857

857 is an odd number, because it is not evenly divisible by 2.

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## Is 857 a perfect square number?

A number is a perfect square (or a square number) if its square root is an integer; that is to say, it is the product of an integer with itself. Here, the square root of 857 is about 29.275.

Thus, the square root of 857 is not an integer, and therefore 857 is not a square number.

Anyway, 857 is a prime number, and a prime number cannot be a perfect square.

## What is the square number of 857?

The square of a number (here 857) is the result of the product of this number (857) by itself (i.e., 857 × 857); the square of 857 is sometimes called "raising 857 to the power 2", or "857 squared".

The square of 857 is 734 449 because 857 × 857 = 8572 = 734 449.

As a consequence, 857 is the square root of 734 449.

## Number of digits of 857

857 is a number with 3 digits.

## What are the multiples of 857?

The multiples of 857 are all integers evenly divisible by 857, that is all numbers such that the remainder of the division by 857 is zero. There are infinitely many multiples of 857. The smallest multiples of 857 are:

## How to determine whether an integer is a prime number?

To determine the primality of a number, several algorithms can be used. The most naive technique is to test all divisors strictly smaller to the number of which we want to determine the primality (here 857). First, we can eliminate all even numbers greater than 2 (and hence 4, 6, 8…). Then, we can stop this check when we reach the square root of the number of which we want to determine the primality (here the square root is about 29.275). Historically, the sieve of Eratosthenes (dating from the Greek mathematics) implements this technique in a relatively efficient manner.

More modern techniques include the sieve of Atkin, probabilistic algorithms, and the cyclotomic AKS test.

## Numbers near 857

• Preceding numbers: …855, 856
• Following numbers: 858, 859

### Nearest numbers from 857

• Preceding prime number: 853
• Following prime number: 859
Find out whether some integer is a prime number