Is 141 a Prime Number?

A prime number should not have factors more than 2 but 141 has 4 divisors. No, 141 is a composite number. 

The divisors of 141 are 1, 3, 47, and 141.  Therefore, 141 is a composite number. Composite numbers are the numbers which have factors more than 2.

A number to be a prime number should follow the criteria, which is that it should not have factors more than 2. 141 has factors more than 2, so it is a composite number.

Given below are a few ways that can be used to find prime or composite numbers.
 

In this method, the divisors of a number are listed, and the number is checked, to be called a prime number. The counting divisors method for 141 would simply be

Divisors of 141 = 1, 3, 47, 141

Number of divisors = 4

The number 141 can be considered composite.

In divisibility method, the prime number only has 2 divisors, which are 1 and itself.

Divisors of 141 = 1, 3, 47, 141.

As 141 has factors more than 2 then it is not a prime number. 
 

We write the prime number chart up to 10, which helps in sorting numbers.

The prime numbers from 100 to 200 are 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199. 141 is not on the list, so it is not a prime number.
 

This method is only used for a composite number. Since 141 is a composite number, prime factorization for 141 is :

3¹ x 47¹

Hence, the prime factors of 141 are 3 and 47.