Is 845 a prime number? What are the divisors of 845?

## Parity of 845

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

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## Is 845 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 845 is about 29.069.

Thus, the square root of 845 is not an integer, and therefore 845 is not a square number.

## What is the square number of 845?

The square of a number (here 845) is the result of the product of this number (845) by itself (i.e., 845 × 845); the square of 845 is sometimes called "raising 845 to the power 2", or "845 squared".

The square of 845 is 714 025 because 845 × 845 = 8452 = 714 025.

As a consequence, 845 is the square root of 714 025.

## Number of digits of 845

845 is a number with 3 digits.

## What are the multiples of 845?

The multiples of 845 are all integers evenly divisible by 845, that is all numbers such that the remainder of the division by 845 is zero. There are infinitely many multiples of 845. The smallest multiples of 845 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 845). 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 29.069). 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 845

• Preceding numbers: …843, 844
• Following numbers: 846, 847

### Nearest numbers from 845

• Preceding prime number: 839
• Following prime number: 853
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