Prime Numbers and Prime Factorization

See also: numbers, GCD and LCM

Prime numbers are positive integers that have exactly 2 factors, that is 1 and itself. For example, 7 is a prime number because its only factors are 1 and 7.

Do you know?

The largest known prime number to date is 274,207,281 − 1.

It was found on 7 January 2016 and has 22,338,618 digits.

The first few primes are 2, 3, 5, 7, 11, 13, 17, 19, and so on. Please note that 1 is not prime because it only has one factor.

You can check whether a number is a prime or not by entering the number below. If the only prime factor of that number is itself, then it's a prime number.

Prime factors are factors of an integer that are prime. Prime factors can be used to find Highest Common Factor and Lowest Common Multiple of two or more integers.

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How to find prime factors of a number?

To find the prime factors of a number we can repeatedly divide by prime numbers.

For example to find the prime factors of 36, we would do the folowing steps.

Another example to find the prime factors of 42.

By Jimmy Sie

See also: numbers, GCD and LCM