Is 819 a prime number? What are the divisors of 819?

## Parity of 819

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

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## Is 819 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 819 is about 28.618.

Thus, the square root of 819 is not an integer, and therefore 819 is not a square number.

## What is the square number of 819?

The square of a number (here 819) is the result of the product of this number (819) by itself (i.e., 819 × 819); the square of 819 is sometimes called "raising 819 to the power 2", or "819 squared".

The square of 819 is 670 761 because 819 × 819 = 8192 = 670 761.

As a consequence, 819 is the square root of 670 761.

## Number of digits of 819

819 is a number with 3 digits.

## What are the multiples of 819?

The multiples of 819 are all integers evenly divisible by 819, that is all numbers such that the remainder of the division by 819 is zero. There are infinitely many multiples of 819. The smallest multiples of 819 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 819). 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 28.618). 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 819

• Preceding numbers: …817, 818
• Following numbers: 820, 821

### Nearest numbers from 819

• Preceding prime number: 811
• Following prime number: 821
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