Is 220 a prime number?

The number 220 has several factors that are capable of dividing the number completely without leaving any remainder. Thus, the number 220 is a non-prime number. The factors of 220 include 1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, and 220.

A number to be a prime number should follow the criteria of having no factors other than 1 and itself. Here, 220 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:

• Counting Divisors Method
• Divisibility Test
• Prime Number Chart
• 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 220 would simply be:

Divisors of 220 = 1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, 220
Number of divisors = 12

The number 220 can be considered composite.
 

In the divisibility 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, a prime number only has 2 divisors: 1 and itself.
The divisors of 220 are 1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, and 220.

Thus, 220 consists of 12 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 is:

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.

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

This method is only used for a non-prime number/composite number. Since 220 is a composite number, the prime factorization for 220 is:

Factors of 220 = 2 × 2 × 5 × 11
 

• Prime Number: A natural number greater than 1 that has exactly two distinct positive divisors: 1 and itself. Examples include 2, 3, 5, and 11.

• Composite Number: A natural number greater than 1 that has more than two distinct positive divisors. For instance, 220 is a composite number because it has multiple factors other than 1 and itself.

• Divisibility Test: A method to determine whether a number can be divided evenly by another number without leaving a remainder. This test is often used to check if a number is prime or composite.

• Prime Factorization: The process of expressing a composite number as the product of its prime factors. For example, 220 can be written as 2²×5×11

• Prime Number Chart: A visual or tabular representation listing all prime numbers within a certain range, often used to quickly identify whether a number is prime. For instance, 220 does not appear on a chart of prime numbers.