Is 1 a composite number

No, the controlling definition of a composite number is one that is evenly divisible by some number other than the number itself or the number 1 (which in this question is redundant). The number 1 is considered neither prime nor composite.

In more detail

• To be a prime, it must be divisible by 1 and itself. Since it cannot do both, it is not prime.
• To be a composite, it must have at least 3 factors, 1 itself, and an additional factor. There is not additional factor.

Many people define a Prime number as an integer that is greater than one whose only positive divisors are one and itself. This definition would exclude 1. There was a time when many people used other definitions and did consider the number 1 to be prime, but this is no longer the case. Some of this has to do with a very important theorem called the "fundamental theorem of arithmetic."

It states that any positive integer has a uniquefactorization into primes. If we allow 1 to be a prime, the theorem really does not work. For example, 6 is 2x3 but it would also be 1x2x3 so the factorization would not be unique.

The number one is instead called a unit.

In addition, there are many mathematical theorems that are moot if the number 1 is included as a prime. Rather than say "primes greater than 1," the number 1 is excluded by default, and only included where necessary.
NO. 1 is neither a composite nor a prime number.
1 is neither a prime, nor a composite number. 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.
No.