Definitions of Prime Numbers and Composite Numbers

Prime number

A prime number is a natural number that is divisible only by itself and by 11.

Composite number

A composite number is a number that can be written as the product of two natural numbers smaller than it, with the exception of 11 and itself.

The number 11 –> is a special number that is neither prime nor composite.
The number 22 –> is the only even number that is prime.

Practice Prime Numbers and Composite Numbers

Examples with solutions for Prime Numbers and Composite Numbers

Exercise #1

Which of the numbers is a prime number?

Video Solution

Answer

11 11

Exercise #2

Is the number equal to n n prime or composite?

n=4 n=4

Video Solution

Answer

Composite

Exercise #3

Is the number equal to n n prime or composite?

n=7 n=7

Video Solution

Answer

Prime

Exercise #4

Is the number equal to n n prime or composite?

n=8 n=8

Video Solution

Answer

Composite

Exercise #5

Is the number equal to n n prime or composite?

n=22 n=22

Video Solution

Answer

Composite

Exercise #6

Is the number equal to n n prime or composite?

n=36 n=36

Video Solution

Answer

Composite

Exercise #7

Is the number equal to n n prime or composite?

n=20 n=20

Video Solution

Answer

Composite

Exercise #8

Is the number equal to n n prime or composite?

n=17 n=17

Video Solution

Answer

Prime

Exercise #9

Is the number equal to n n prime or composite?

n=42 n=42

Video Solution

Answer

Composite

Exercise #10

Is the number equal to n n prime or composite?

n=10 n=10

Video Solution

Answer

Composite

Exercise #11

Is the number equal to n n prime or composite?

n=23 n=23

Video Solution

Answer

Prime

Exercise #12

Is the number equal to n n prime or composite?

n=19 n=19

Video Solution

Answer

Prime

Exercise #13

Is the number equal to n n prime or composite?

n=29 n=29

Video Solution

Answer

Prime

Exercise #14

Which of the numbers is a prime number?

Video Solution

Answer

11 11

Exercise #15

Which of the numbers is a prime number?

Video Solution

Answer

7 7

Topics learned in later sections

  1. Prime Factorization
  2. Prime Factorization with Exponents
  3. Divisibility Rules for 2, 4, and 10
  4. Divisibility Rules for 3, 6, and 9