What is a prime?
A number is a number that has exactly two - itself and 1. There are an infinite number of prime numbers.
Numbers that have more than two factors are called . They can be expressed as a of prime numbers.
The number 1 is not a prime number or a composite number. It is often referred to as a unit.
The only even prime number is 2. All other even numbers can be divided by 2
Knowledge of prime numbers helps in understanding of highest common factor (HCF), lowest common multiple (LCM) and product of prime factors.
Knowledge of prime numbers is helpful in supporting understanding of (HCF), and .
- A prime number has exactly two – itself and 1. This means it also only has one .
- A prime number is only divisible by itself and 1
Prime numbers are used to:
- find the (HCF) and of two or more numbers.
- break down a into a product of its prime factors.
Practise what you've learned about prime numbers with this quiz.
Prime numbers are important in creating digital security systems (cybersecurity).
The prime numbers used to secure data through encryption are extremely large. You can multiply two very large prime numbers together, but it is difficult to break that number back down and find the factors.
This is part of what keeps information secure.
