Is 178 a prime number?

The number 178 has got 4 factors, that are capable of dividing the number completely without leaving any remainder. Thus the number 178 is a non-prime number. The factors of 178 include 1, 2, 89, and 178.

A number to be a prime number should follow the criteria, which is that it should not have factors more than 2. Here, 178 has more than 2 factors, hence making it a composite number.

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

The different methods we can use to check if a number is a prime number are explained below.

1. Counting Divisors Method
2. Divisibility Test
3. Prime Number Chart
4. Prime Factorization
    

For the counting divisors method, it is to be checked whether the number is divisible by any numbers other than 1 and the number itself.

The counting divisors method for 178 would simply be

Divisors of 178 = 1, 2, 89, 178
Number of divisors = 4

The number 178 can be considered composite.
 

In the division test, we try to divide the number by any of the prime numbers. If we cannot, then it is considered a prime number.

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

The divisors of 178 are 1, 2, 89, and 178.

Thus, 178 consists of 4 factors that divide it completely without any remainder.
 

The prime number chart is the list of prime numbers starting from 2 to infinity.

The list of prime numbers under 100 are;

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97.

178 is not present in the list, it is not a prime number.
 

This method is only used for a non-prime number/composite number. Since 178 is a composite number, the prime factorization for 178 is:

Factors of 178 = 2 × 89
 

• Prime Number: A natural number greater than 1 that has no positive divisors other than 1 and itself. Examples include 2, 3, 5, and 7.

• Composite Number: A positive integer greater than 1 that has more than two divisors. For example, 178 is a composite number because it has divisors other than 1 and itself, such as 2 and 89.

• Divisor: A number that divides another number exactly, without leaving a remainder. For example, the divisors of 178 are 1, 2, 89, and 178.

• Divisibility Test: A method used to determine whether one number is divisible by another. In this context, divisibility tests help identify if 178 can be divided by smaller prime numbers.

• Prime Factorization: The process of expressing a composite number as the product of its prime factors. For 178, the prime factorization is 2 × 89.