Types of Number – Prime Number

Among the other types of numbers like even numbers, odd numbers, and co-prime numbers, prime numbers are one of them. Usually, prime numbers are seen as odd numbers, but they have a slight difference that makes them different from odd numbers. It is known that even numbers are divisible by 2, but 2 is also a prime number since it can only be divided by 1 and itself. We can apply the same logic to 1 which has only one factor and is not a prime number. As we will see in this article, prime numbers have some other important uses in mathematics.

What is Prime Numbers?

Prime Numbers are those whole numbers that cannot be formed by adding two other whole numbers together. If a number has a value greater than 1 and it is not the product of two numbers, it is considered a prime number. If it’s composed of two whole numbers, it is referred to as a co-prime number. The only factors of 15 are 1 and 15, which makes 15 a prime number; however, 22 has three factors of 1, 2, 11, and 22, making it a co-prime number. This is because 22 can be formed by multiplying 11 and 2 or 22 and 1, but 15 is a prime number as it cannot be factored.

What is the Definition of Prime Numbers?

Considering what we have seen so far, prime numbers can be defined as positive integers that have no other integers as divisors except for 1 and themselves. It is possible to express the prime positive integer as p > 1, where p is a prime number. As the prime number is divisible by any other number except 1, it can be said that it has no other. It can also be understood as the number that cannot be divided into two equal groups. This is because a number can only be divided into two equal groups if it has factors and prime numbers have none. For example, if we take 5, it cannot be divided into two equal parts and hence is a prime number.

How to identify a prime number?

A prime number can be identified using the following ways:

• Using formula-1: It is possible to calculate all prime numbers greater than 50 by applying the formula ‘n2 + n + x’, where x is a multiple of 10. The expression would look like this if we substituted a whole number, for example, 0:

02 + 0 + 51 = 0 + 51 = 51

Similarly, If we do it for another whole number like 1, we will get:

12 + 1 + 51 = 2 + 51 = 53

• Using formula-2: In mathematics, all the prime numbers except 2 and 3 can be expressed in the form of ‘6n + 1’ or ‘6n – 1’. Suppose, if we put 1 as a whole number in the expression, then:

6(1) – 1 = 5 

Or, 6(1) + 1 = 7

Hence, we can say that the numbers 5 and 7 are prime numbers.

What are the Properties of Prime Numbers?

Like any other type of number, prime numbers have certain properties, including:

• Prime numbers cannot be factorized since they only have two factors, which are 1 and the number itself.
• It is said to be a prime number if the whole number is greater than 1 and has no divisor except for 1.
• In spite of the fact that any number divisible by 2 is an even number, 2 is considered a prime number since it also has only two factors. It is, therefore, called an even prime number.
• Due to the fact that a prime number is made up of two factors, 1 and the number itself, any number can be written as the product of two prime numbers.

What are Odd Prime numbers?

Prime numbers are very similar to odd numbers but the only difference is that odd numbers can either be factored or not depending on the number at the unit place, but prime numbers cannot be factored. Odd prime numbers, therefore, have the properties of both odd and prime numbers. A few odd prime numbers are 2, 3, and 5.

Conclusion

Number theory uses prime numbers extensively, as do other mathematical calculations. The concept of prime numbers is said to be used in different areas of mathematics, such as abstract algebra and elementary geometry. Quantum mechanics, as well as evolutionary biology, apply to prime numbers. The purpose of this article was not simply to provide a basic understanding of prime numbers, but rather to provide an in-depth understanding of them such as their definition, properties, types, and identification. The prime numbers, then, can be said to be an integral part of mathematics taking into account the various fields in which it is used.