# Do you know Why is 57 not a Prime Number?

A prime number is a positive integer greater than 1 that is divisible by only 1 and itself. For example, 2, 3, 5, 7, 11, and 13 are prime numbers.

## Why 57 is not a Prime Number

The number 57 is not a prime number because it can be divided evenly by other numbers besides 1 and itself. Specifically, 57 is divisible by 3 and 19.

To elaborate, when we divide 57 by 3 we get a quotient of 19 and no remainder. And when we divide 57 by 19 we get a quotient of 3 and no remainder. This means that 3 and 19 are factors of 57. Since a prime number can only be divided by 1 and itself, and 57 can be divided by 3 and 19, 57 is not a prime number.

It’s also possible to use the process of elimination, for example by dividing 57 by 2,3,4,5,6,7,8,9,10 and so on, and you will notice that 57 is not a prime number because it can be divided by 3 and 19.

In summary, 57 is not a prime number because it can be divided evenly by numbers other than 1 and itself, specifically 3 and 19.

## List all Prime Numbers Between 8 and 28

Here is a list of all the prime numbers between 8 and 28:

• 11
• 13
• 17
• 19
• 23
• 29

Note that 8 is not a prime number because it can be divided by 2 and 4. Also 28 is not a prime number as it can be divided by 2 and 14.

## History of Prime Numbers

The concept of prime numbers dates back to ancient times, with early references to primes appearing in the work of the Greek mathematicians Euclid and Eratosthenes. Euclid’s “Elements,” written around 300 BCE, includes a proof that there are infinitely many prime numbers and also describes the Sieve of Eratosthenes, an algorithm for finding all prime numbers up to a given limit.

The ancient Greeks also recognized the importance of prime numbers in number theory and in the study of the properties of numbers more generally. They used prime numbers in a number of ways, such as in the construction of musical scales and in the solution of certain types of mathematical problems.

During the Middle Ages, the study of prime numbers was largely confined to the Islamic world, where scholars such as Al-Karaji and Al-Farisi made significant contributions to the field. In the 16th century, the German mathematician Peter Apian used prime numbers to create the first known table of prime numbers.

In the 17th century, the French mathematician Pierre de Fermat formulated some of the first known results in the theory of numbers, including Fermat’s Little Theorem, which states that if p is a prime number, then for any integer a, the number ap – a is an integer multiple of p. Fermat’s work laid the foundation for the development of modern number theory.

In the 18th and 19th centuries, the study of prime numbers was further advanced by mathematicians such as Leonhard Euler, Carl Friedrich Gauss and Sophie Germain. Their work led to the discovery of important results such as the law of quadratic reciprocity, the prime number theorem and the Riemann Hypothesis.

Today, the study of prime numbers continues to be an active area of research in mathematics, with ongoing work in areas such as number theory, cryptography, and computer science.

In summary, the history of prime numbers can be traced back to ancient Greece, and throughout the centuries, many mathematicians have contributed to the field, leading to the development of number theory and many important results in mathematics.