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126 LearnersLast updated on December 1st, 2024
Is 129 a Prime Number?
Do you feel like checking for prime numbers can be tricky? Determining a prime number is easy. Prime numbers are used in encryption. Here, we discuss the topic called ‘Is 129 a prime number?’.
Why is 129 not a Prime Number?
Since 129 has 4 factors, it is not a prime number. The basic methods to check if a number is prime are the counting divisors method, divisibility method, prime number chart, and prime factorization.
Using the Counting Divisors Method
This method will find the total number of divisors of the given number. If there are more than two divisors, then the given number is composite, not prime.
The divisors of 129 = 1, 3, 43, 129
Therefore, 129 is not prime.
Using the Divisibility Test Method
The divisibility method determines whether a number is composite or not. Make use of the divisibility rule of 2 (if the number is even), the divisibility rule of 3 (if the sum of digits is a multiple of 3), and so on.
The number 129 is divisible by 3, we use the divisibility rule of 3. Hence, factors of 129 are 1, 3, 43, and 129.
Using Prime Number Chart
This method will check if a number is prime or not with the help of a prime number chart. Only if the number is seen in the chart, then it's a prime.
Using the Prime Factorization Method
Prime Factorization expresses the product of prime factors of composite numbers in exponential form. The prime factors of 129 are 3 and 43.
The prime factorization of 129 → 31 × 431
Glossaries for ‘Is 129 a Prime Number’
- Prime Number: Natural number with two factors. For example, numbers like 29, 43, 91, etc.
- Composite Number: Numbers with more than two factors. For example, numbers like 54, 63, 85, 169, and so on.
- Prime Factorization: Method to express the product of prime factors using exponents.