Is 816 a prime number? What are the divisors of 816?

## Parity of 816

816 is an even number, because it is evenly divisible by 2: 816 / 2 = 408.

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## Is 816 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 816 is about 28.566.

Thus, the square root of 816 is not an integer, and therefore 816 is not a square number.

## What is the square number of 816?

The square of a number (here 816) is the result of the product of this number (816) by itself (i.e., 816 × 816); the square of 816 is sometimes called "raising 816 to the power 2", or "816 squared".

The square of 816 is 665 856 because 816 × 816 = 8162 = 665 856.

As a consequence, 816 is the square root of 665 856.

## Number of digits of 816

816 is a number with 3 digits.

## What are the multiples of 816?

The multiples of 816 are all integers evenly divisible by 816, that is all numbers such that the remainder of the division by 816 is zero. There are infinitely many multiples of 816. The smallest multiples of 816 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 816). 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 28.566). 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 816

• Preceding numbers: …814, 815
• Following numbers: 817, 818

### Nearest numbers from 816

• Preceding prime number: 811
• Following prime number: 821
Find out whether some integer is a prime number