质因数分解计算器 — 公式

Prime Factorization

What Is It?

Every integer greater than 1 can be written as a product of prime numbers in exactly one way (Fundamental Theorem of Arithmetic).

Method: Trial Division

1. Start with the smallest prime (2) 2. If it divides the number, it is a factor; divide and repeat 3. If not, try the next prime (3, 5, 7, 11, ...) 4. Stop when you reach sqrt(n)

Divisibility Quick Checks

By 2: last digit is even

By 3: digit sum is divisible by 3

By 5: last digit is 0 or 5

This calculator shows divisibility checks. For full factorization of large numbers, a step-by-step approach is needed.