Composite number

A composite number is one that can be formed by multiplying some integers* together. For example 18 is composite because It follows that composite numbers are never prime numbers. For more see Prime numbers.

Other number topics

• Introduction to numbers
• The number line

Scalar numbers

• What are scalars?
• Real numbers
• Integers
• Natural Numbers
• Positive numbers
• Negative numbers
• The uses of negative numbers
• Scientific notation (normal form)
• Complex numbers
• Imaginary numbers

Counting numbers

• Counting numbers (whole numbers)
• Cardinal numbers
• Cardinality
• Ordinal numbers

Numbers that have factors

• Prime numbers
• Composite (opposite of prime) numbers
• Rational numbers
• Irrational numbers

Special values

• i
• j
• pi