Is 643 a Prime Number?

Is 643 a prime number? How do you know that 643 is prime or composite? Let us first understand what makes a number 'prime'. If a number has only 2 factors (1 and the number itself), then it is a prime number. If the number has more than 2 factors, then it is composite. Now, what do you think of 643? Is 643 a prime number? "Yes, 643 is a prime number." Since 643 has only 2 factors i.e. 1 and 643, it is a prime number. Let's study this in detail.

• Is 643 a prime number? - Yes
• Is 643 a composite number? - No
• Prime Factors of 643 - 643
• Factors of 643 - 1, 643
• Is 643 a perfect square? - No

Is 643 a Prime Number?

Yes, 643 is a prime number. The number 643 is divisible only by 1 and the number itself. For a number to be classified as a prime number, it should have exactly two factors. Since 643 has exactly two factors, i.e. 1 and 643, it is a prime number.

How is 643 a Prime Number?

To understand whether 643 is composite or prime, it is important to find its factors.

Factors of 643: 1, 643

Therefore, we can say that 643 is a prime number since it has only 2 factors.

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Is 643 a Composite Number?

No, since 643 has only two factors, i.e. 1 and 643. In other words, 643 is not a composite number because 643 doesn’t have more than 2 factors.

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Fun Facts:

• A semiprime number is a composite number that is the product of exactly two prime numbers. Example - 697 is semiprime, since 697 can be written as 17 × 41.
• A palindrome prime is a prime number that when read in reverse order results in the same number. Examples - 787, 373, 353
• 23 is the smallest prime number having consecutive digits.

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