# What is a Prime Number Mean in Math?

A number is said to be a prime number if is the number that has only two factors, which are, 1 and the number itself. Consider an example of number 11, which has only two factors 1 and 11. This means it is a prime number.

Considered at another example of the number 8, which has two or more **factors**, i.e., 1, 2, 4, and 8. This means 8 is not a prime number but 8 is said to be a **composite number**. in this article learn about the prime number.

**What are prime numbers?**

A number is said to be a prime number if is the number that has only two factors, which are, 1 and the number itself. In other words, a number greater than 1 that is divisible only by 1 and itself, is defined as a prime number.

**List of prime number**

There are prime numbers from 1 to 50. The complete list of prime numbers from 1 to 50 is given below:

List of number | Prime number |

Between 1 and 10 | 2, 3, 5, 7 |

Between 11 and 20 | 11, 13, 17, 19 |

Between 21 and 30 | 23, 29 |

Between 31 and 40 | 31, 37 |

Between41 and 50 | 41, 43, 47 |

**Properties of prime number**

Important properties of prime numbers are given below:

- A prime number is a whole number greater than 1.
- It has exactly two factors, that is, 1 and the number itself.
- There is only 2 even prime number.
- Any two prime numbers are always co-prime to each other.
- Every number can be expressed as the product of prime numbers.

**Easy way to calculate the prime number**

There are distinct ways to calculate prime numbers. Let us go through two of these methods.

**Step1:** Substitute whole numbers for n in the formula’n^{2} + n + 41′. This formula will give you all the prime numbers larger than 40. Let us substitute a few whole numbers and check.

- Let us check this formula, n
^{2}+ n + 41, for the number 0, So, 0^{2}+ 0 + 41 = 0 + 41 = 41 - Let us check this formula, n
^{2}+ n + 41, for the number 1, So, 1^{2}+ 1 + 41 = 2 + 41 = 43 - Let us check this formula, n
^{2 }+ n + 41, for the number 2, So, 2^{2}+ 2 + 41 = 6 + 41 = 47

Therefore, we can find all the prime numbers larger than 40 using this formula.

**Method 2:**

Every prime number, apart from 2 and 3, can be written in the form of ‘6n + 1 or 6n – 1’. So, if we have any number different from 2 and 3, we can check if it is prime or not by trying to express it in the form of 6n + 1 or 6n – 1

- Let us check this formula, 6n – 1, for the number 1, So, 6(1) – 1 = 5
- Let us check this formula, 6n + 1, for the number 0, So, 6(2) + 1 = 13

Now, we know that the numbers 5, 7, 11, and 13 are prime.

**Summary:**

- The only 2 is an even prime number.
- All prime numbers are not odd. This is because 2 is an even number and a prime number as well. In fact, 2 is the only even prime number.
- 1 is neither a prime number nor a composite number

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