Is 655 a prime number? What are the divisors of 655?

## Parity of 655

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

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## Is 655 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 655 is about 25.593.

Thus, the square root of 655 is not an integer, and therefore 655 is not a square number.

## What is the square number of 655?

The square of a number (here 655) is the result of the product of this number (655) by itself (i.e., 655 × 655); the square of 655 is sometimes called "raising 655 to the power 2", or "655 squared".

The square of 655 is 429 025 because 655 × 655 = 6552 = 429 025.

As a consequence, 655 is the square root of 429 025.

## Number of digits of 655

655 is a number with 3 digits.

## What are the multiples of 655?

The multiples of 655 are all integers evenly divisible by 655, that is all numbers such that the remainder of the division by 655 is zero. There are infinitely many multiples of 655. The smallest multiples of 655 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 655). 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 25.593). 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 655

• Preceding numbers: …653, 654
• Following numbers: 656, 657

### Nearest numbers from 655

• Preceding prime number: 653
• Following prime number: 659
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