A natural number (i.e. 1, 2, 3, 4, 5, 6, etc.) is called a prime number (or a prime) if it has exactly two positive factors, 1 and the number itself. Natural numbers that have more than two positive factors are called composite. 1 has only one positive factor i.e. no.1 only. Hence 1 is neither prime nor composite.
Also, what is the smallest prime number and why?
1 is the smallest natural number but it has only 1 factor that is 1 itself. Therefore, 1 cannot be considered as a prime number. Next number 2 is the smallest even prime number. as 1×1=1,so it is not prime no.
Why is the number 1 not a prime number?
Answer One: By definition of prime! An integer greater than one is called a prime number if its only positive divisors (factors) are one and itself.
What is the lowest composite number?
A composite number is a positive integer which is not prime (i.e., which has factors other than 1 and itself). The first few composite numbers (sometimes called "composites" for short) are 4, 6, 8, 9, 10, 12, 14, 15, 16, (OEIS A002808), whose prime decompositions are summarized in the following table.