Is 33 a Prime Number?

On the basis of factors present, a number can be differentiated into Prime and Composite numbers. A prime number is a natural number which is divisible exactly by 1 and the number itself, whereas a composite number has more than 2 factors. Here, 33 has more than 2 factors ie. 1, 3, 11 and 33 therefore it is not a prime number.

 
Few properties of prime numbers are as follows - 

• A prime number is always positive and greater than 1.
• The only even prime number is number 2
• A prime has exactly two factors: 1 and itself.

Since 33 has more than 2 factors(1, 3, 11, 33), it is a composite number and not a prime numbe
 

The number 33 is not included in prime number chart because it has more than 2 factors. A prime number is divisible only by 1 and the number itself. Few methods for finding a number as prime or not is discussing below - 
 

In this method, to check if a number is prime or not, we list all the divisors of the number and count them. The counting divisors method for 33 would simply be

Divisors of 33=1,3,11,33

Number of divisors=4

The number 33 can be considered composite, as it has more than two factors.

In this method, a prime number is divisible only by 2 factors : 1 and itself.

Divisors of 33 =1,3,11,33

As 33 has factors more than 2 then it is not a prime number. 
 

Prime numbers falling between the range of 1 and 35 are as follows - 2, 3, 5, 7, 11, 13, 17, 19, 23, 29 and 31. Since 33 is not in the list, it is not a prime number.
 

This method is used for only composite number. Since 33 is a composite number, the prime factorization for 33 is :
Factors of 33 = 3 × 11.

Both 3 and 11 are prime numbers.

Therefore, 33 can be expressed as the product of two prime numbers that is 3 and 11 which makes it a composite number.

• Prime Factorization: Prime factorization is a method of expressing a number as a product of its prime factors. For example, the prime factorization of 6 is 2×3.

• Multiple: A multiple of a number is the result of the product between that number and an integer . Some multiples of 28 are 28, 56, 84, 112, 140 and so on.

• Composite numbers: Composite number are the numbers that have more than 2 factors. Some examples of composite numbers are 4, 6, and 9.

• Whole Numbers: Whole numbers are the integers that are not in decimal or fraction form. Some examples of whole numbers are 1, 2, 3, 4, 5, and so on