Is 3 a prime number?

Number can be of two types, Prime and Composite.

To check if a number is composite or not, look at its factors. If a number has more than two factors, then it's composite. For a number to be prime, the number should have only two factors, that are 1 and the number itself.

Number 3 has only two factors, 1 and 3, so it is prime.

There are two conditions to be followed to determine whether a number is prime or not:

• The number should have only two factors

• The total number of divisors should be two.

When a number possesses the above-mentioned points, then it can be determined as a prime number.

Here are some methods that can be used to check whether a number is prime or not:

• Counting Divisors Method

• Divisibility Test

• Prime Number Chart Method

• Prime Factorization Method

This method is used to determine whether the number is prime or not by checking its number of divisors. 

• Divisors for 3: 1, 3

• Total No:of divisors: 2

Number 3 has 2 divisors and therefore, we can say that 3 is a prime number.
 

The divisibility test method checks whether the 3 can be divided by numbers except 1 and 3.

• To check whether a number is divisible by 2, the number should end in 2 or any other even number. Here, 3 is not divisible by 2.

• To check whether a number is divisible by 3, take the sum of the digits and check if it's a multiple of 3. Here, 3 is a multiple of 3, and we can say that 3 is divisible by 3.

• To check whether a number is divisible by 4, the sum of the last two digits of the given number should be a multiple of 4. Since 3 is a single-digit number and not a multiple of 4, number 3 is not divisible by 4.

• To check whether a number is divisible by 5, the number should either end in 0 or 5. Here, 3 doesn’t end with 0 or 5. So 3 is not divisible by 5.
   

The prime chart method lists all the prime numbers between 1 and 100. The chart given below shows the prime numbers between 1 and 100:
 

We can see that number 3 appears in the chart. Hence, 3 is a prime number.

The prime factorization method is used to break down the number into its prime factors. Here, 3 can be prime factorized into 1 and 3 as its prime factors.

• Divisor: Number that divides another number.

• Factors: Whole numbers that divide the given number without any remainder.

• Prime numbers: Numbers with two factors.

• Composite numbers: Numbers having factors other than 1 and the number itself.