Question

which number is neither a prime number nor a composite number ???

Answer 1

Prime number : A number which has only 2 factors -  1 and itself.

Ex: 2,3,5,7,11,13,17,19....

Composite number : A number which can be divided by the numbers other than 1 and itself.

Ex: 4,6,8,9....

Now,

The answer to your question is 1. It is neither a prime number nor a composite number.

Hope it helps!