Prime Factorization 素因数分解😸 - 令和義塾🛡中高生・高卒生・教員・留学志望者のための学習塾

When a natural number is expressed in the form as the product of several natural numbers, one by one, they are called factors of the original natural number. As for 243, it can be expressed as 9 times 27 or 3 times 81, so 3,9, 27, 81 are the factors of 243. Natural numbers which have no divisors other than 1 and itself are called prime numbers. Prime numbers less than 25 are 2, 3, 5, 7, 11, 13, 17, 19, and 23.

Decomposing natural numbers into the form of products of factors which are the prime numbers (prime factors) are called prime factorization. The prime factorization of 105 is 105 equals 3 times 5 times 7, and 495 equals 3 squared times 5 times 7.

When the numbers become large, if you divide by prime numbers you can do the prime factorization. Dividing 660 in order from the smallest prime number, it becomes 660equals 2 squared times 3 times 5 times 11.