Is 38 a Prime Number?

38 is not a prime number. But according to what we are saying, why is it not a prime number? Let's understand that, firstly, the number set is of two parts:

• Prime number

• composite numbers

And using one of the methods we're going to introduce you to, we will find that indeed 93 is not a prime.

We could find that a number is prime if it has 2 factors only, 1 and the number itself, and only 2 divisors. It means that a number, not satisfying these conditions, cannot be a prime number.

However, there are pretty simple methods to determine whether a number is prime or not:

• Count Divisor Method

• Divisibility Test

• Prime Number Table

• Prime Factorization
   

The name implies: We’re counting how many divisors a given number has, and then saying that number is prime. It is easy to learn. With that said, let’s see what steps are there in this method.

• First is to count how many the number holds in divisors.

• We can then see that 38 has more than 2 divisors: 1,2,19 and 38.

We can see that number 38 has 4 divisors. Thus, we see that it doesn’t fulfill the criteria needed for a prime number. And so it is not a prime number.

In this case, we'll see if 38 can be divided into any other number. Now if it gets divided then that is not a prime number. So let’s check for 2,3,5 and 7.

• Since 38 is an even number, we can say that 38 is divisible by 2.

• Since the sum of the digits is 11. 11 is not divisible by 3 as 11 is not a multiple of 3. 

• 38 is not ending with a 0 or a 5. Therefore, it is not divisible by 5.

• We can see if 38 is divisible by 7 with a simple trick. We examine the last digit of 8. Then we double that 8, and take the other digit, which is 3, and subtract it out from whatever we double. So, we do 16–3 = 13. Here is a change of structure from that above is ineffective because 13 is not divisible by 7, so 38 is not a multiple of 7.

We know 38 can be divided by two of the above-mentioned numbers, therefore it is not a prime number.
 

Here, we will be using a chart that will contain all the prime numbers between 1 and 100. If the given number appears in the list, it is not a prime number. 
 

We can see that 38 does not appear here. So, it is not a prime number.

We use this method of breaking large numbers into small numbers, then checking the factors. It works only for composite numbers. 

The factors of 38 are 2 and 19. Since there are more than two factors for 38, we can not title 38 a prime number.
 

• Factor- A number, if multiplied with another number, gives us the required number. Example, 7×2=14, 7×3=21. In that, 2 and 3 are factors.

• Composite number- If the number of factors for the given number is above 2, then that number is a composite number.

• Prime numbers- Any number with only 2 factors is called a prime number. The factors will be 1 and itself. For example, 2 and 3 are prime numbers because they have only 2 factors.

• Test of Divisibility- It is a test made to determine by how many numbers a number is divisible by other numbers. For example, 4. When we do the divisibility test, then we get it to be divisible by both 1, 2 and 4.