Is 1480 a Prime Number?

There are two types of numbers, mainly — Prime numbers and composite numbers, depending on the number of factors. A prime number is a natural number that is divisible only by 1 and itself. For example, 3 is a prime number because it is divisible by 1 and itself.

A composite number is a positive number that is divisible by more than two numbers. For example, 6 is divisible by 1, 2, 3, and 6, making it a composite number.

Prime numbers follow a few properties like: 

• Prime numbers are positive numbers always greater than 1. 
• 2 is the only even prime number. 
• They have only two factors: 1 and the number itself. 
• Any two distinct prime numbers are co-prime numbers because they have only one common factor, which is 1.
• As 1480 has more than two factors, it is not a prime number.

The characteristic of a prime number is that it has only two divisors: 1 and itself. Since 1480 has more than two factors, it is not a prime number. Several methods are used to distinguish between prime and composite numbers. These methods include: -

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

The method in which we count the number of divisors to categorize numbers as prime or composite is called the counting divisors method. Based on the count of the divisors, we categorize numbers. -

• If there is a total count of only 2 divisors, then the number would be prime. -
• If the count is more than 2, then the number is composite.

Let’s check whether 1480 is prime or composite.

Step 1: All numbers are divisible by 1 and itself.

Step 2: Divide 1480 by 2. It is divisible by 2, so 2 is a factor of 1480.

Step 3: Divide 1480 by 3. It is not divisible by 3, so 3 is not a factor of 1480.

Step 4: You can simplify checking divisors up to 1480 by finding the root value. We then need to only check divisors up to the root value.

Step 5: When we divide 1480 by 2, 4, 5, and other numbers, it is divisible by several of these.

Since 1480 has more than 2 divisors, it is a composite number.

We use a set of rules to check whether a number is divisible by another number completely or not. This is called the Divisibility Test Method. -

Divisibility by 2: The number in the ones' place is 0. Zero is an even number, which means that 1480 is divisible by 2. 

Divisibility by 3: The sum of the digits in the number 1480 is 13. Since 13 is not divisible by 3, 1480 is also not divisible by 3. 

Divisibility by 5: The unit’s place digit is 0. Therefore, 1480 is divisible by 5. 

Divisibility by 7: The last digit in 1480 is 0. To check divisibility by 7, double the last digit (0 × 2 = 0). Then, subtract it from the rest of the number (148 - 0 = 148). Since 148 is not divisible by 7, 1480 is also not divisible by 7. 

Divisibility by 11: The sum of the digits in odd positions is 9, and the sum of the digits in even positions is 4. This would mean that 1480 is not divisible by 11.

Since 1480 is divisible by factors other than 1 and itself, it has more than two factors. Therefore, it is a composite number.

The prime number chart is a tool created by using a method called “The Sieve of Eratosthenes.” In this method, we follow these steps:

Step 1: Write numbers from 1 to 100 in 10 rows and 10 columns.

Step 2: Leave 1 without coloring or crossing, as it is neither prime nor composite.

Step 3: Mark 2 because it is a prime number and cross out all the multiples of 2.

Step 4: Mark 3 because it is a prime number and cross out all the multiples of 3.

Step 5: Repeat this process until you reach the table consisting of marked and crossed boxes, except 1.

Through this process, we will have a list of prime numbers from 1 to 100. Since 1480 is not present in this list, it is a composite number.

Prime factorization is a process of breaking down a number into prime factors. Then multiply those factors to obtain the original number.

Step 1: We can write 1480 as 2 × 740.

Step 2: Further break down 740 into 2 × 370.

Step 3: Break 370 into 2 × 185.

Step 4: 185 can be broken down into 5 × 37, where 37 is a prime number.

Hence, the prime factorization of 1480 is 2 × 2 × 2 × 5 × 37.

• Composite numbers: Natural numbers greater than 1 that are divisible by more than 2 numbers are called composite numbers. For example, 12 is a composite number because 12 is divisible by 1, 2, 3, 4, 6, and 12. 

• Prime numbers: Numbers greater than 1 that have no divisors other than 1 and themselves. 

• Divisibility rules: Guidelines that help determine if one number is divisible by another without performing full division. 

• Prime factorization: Breaking down a number into its basic prime number multipliers. 

• Sieve of Eratosthenes: An ancient algorithm used to find all prime numbers up to a specified integer.