Advertisement

**No, number 19 is not a composite number.**- Nineteen is not a composite number, because it's only divisors are one and itself.

- Yes the number 19 is a prime number.

**Prime factors of 19: 1 * 19**

- So, if n > 0 is an integer and there are integers 1 < a, b < n such that n = a * b, then n is composite. By definition, every integer greater than one is either a prime number or a composite number. The number one is a unit, it is neither prime nor composite. For example, the integer 14 is a composite number because it can be factored as 2 * 7. Likewise, the integers 2 and 3 are not composite numbers because each of them can only be divided by one and itself.
- Every composite number can be written as the product of two or more (not necessarily distinct) primes, for example, the composite number 299 can be written as 13 * 23, and that the composite number 360 can be written as 23 * 32 * 5; furthermore, this representation is unique up to the order of the factors. This is called the fundamental theorem of arithmetic.

A composite number is a positive integer that has at least one positive divisor other than one or the number itself. In other words, a composite number is any integer greater than one that is not a prime number.

A composite number (or simply a composite) is a natural number, that can be found by multiplying prime numbers. For example, the number 9 can be found by multiplying 3 by 3, and the number 12. You get it by multiplying 3, 2 and 2. All natural numbers (greater than 1) can be put in one of the two classes. Either the number is prime. Or the number is not prime. It can be found by multiplying together other primes. The same prime number can be used several times, as in the example with 12 above. This is known as the fundamental theorem of arithmetic.

A composite number (or simply a composite) is a natural number, that can be found by multiplying prime numbers. For example, the number 9 can be found by multiplying 3 by 3, and the number 12. You get it by multiplying 3, 2 and 2. All natural numbers (greater than 1) can be put in one of the two classes. Either the number is prime. Or the number is not prime. It can be found by multiplying together other primes. The same prime number can be used several times, as in the example with 12 above. This is known as the fundamental theorem of arithmetic.