We can't answer this accurately if you don't tell us the groups to choose from.
Nobody invented them, they are just names for numbers. A prime number has only 2 factors which are 1 and itself. Composite numbers are everything else except 1 and 0. 1 and 0 are neither prime, nor composite.
The property of prime or composite is not defined for the number 1, just as it is not defined for any number that has a fractional part. There are no special names for numbers that are not prime nor composite.
fraction
A fraction names part of a region or part of a group. The top number of a fraction is called its numerator and the bottom part is its denominator. They are separated by a line called a "fraction bar."
1,2,3,5,6,10,15,30
1,2,3,4,6,12
We can't answer this accurately if you don't tell us the groups to choose from.
13 and 19 aren't composite. 1,2,5,10 1,13 1,2,3,6,9,18 1,19
the set of factors
As a product of its prime factors: 2*3*3*5*139 = 12510 or as 2*32*5*139 = 12510
1,3,9,27
One and the number itself.
1, 3, 9, 27
Any prime number only has two factors, one and the number itself.
1 and 71
1,2,3,4,6,9,12,18,36