A number is composite if has a divisor of itself and unity.
As we have seen there are numbers that have different divisors, besides themselves and unity.
As we can descompose it into prime factors will call composite.
Then a composite number is one that can be decomposed into distinct prime factors differents to itself and unit.
If we have 12 objects, we can place them forming a box of these four ways that are essentially two.
- 3·4 (4·3)
- 2·6 (6·2)
These two forms of placement correspond to decomposition of 12 in prime numbers different from itself and unity (2.3). Other numbers, such as 7, can not be represented by points in accordance with a rectangular shape.
We say that 12 is a composite number and 7 is prime number.
To decomposing a number into its prime factors is explained in factoring.