Visual LCM & GCD (HCF) Prime Factor Venn & Tree Solver
Given prime factorizations $A = \prod p_i^{a_i}$ and $B = \prod p_i^{b_i}$, the Greatest Common Divisor takes minimum exponents $\gcd(A,B) = \prod p_i^{\min(a_i,b_i)}$, the Least Common Multiple takes maximum exponents $\text{lcm}(A,B) = \prod p_i^{\max(a_i,b_i)}$, and $\gcd(A,B) \times \text{lcm}(A,B) = A \times B$.
GCD(A,B) × LCM(A,B) = A × BInputs & Parameters (2)
20-Row Comparison Table
| # | First Integer (A) | Prime Factor Count Ω(N) | LCM(N, M) | Prime Factors of N |
|---|---|---|---|---|
| 01 | 2 | 2 | 126 | 2 |
| 02 | 40 | 2 | 2,520 | 2 × 2 × 2 × 5 |
| 03 | 78 | 6 | 1,638 | 2 × 3 × 13 |
| 04 | 115 | 1 | 14,490 | 5 × 23 |
| 05 | 153 | 9 | 2,142 | 3 × 3 × 17 |
| 06 | 191 | 1 | 24,066 | 191 |
| 07 | 229 | 1 | 28,854 | 229 |
| 08 | 267 | 3 | 11,214 | 3 × 89 |
| 09 | 304 | 2 | 19,152 | 2 × 2 × 2 × 2 × 19 |
| 10 | 342 | 18 | 2,394 | 2 × 3 × 3 × 19 |
| 11 | 380 | 2 | 23,940 | 2 × 2 × 5 × 19 |
| 12 | 418 | 2 | 26,334 | 2 × 11 × 19 |
| 13 | 455 | 7 | 8,190 | 5 × 7 × 13 |
| 14 | 493 | 1 | 62,118 | 17 × 29 |
| 15 | 531 | 9 | 7,434 | 3 × 3 × 59 |
| 16 | 569 | 1 | 71,694 | 569 |
| 17 | 607 | 1 | 76,482 | 607 |
| 18 | 644 | 14 | 5,796 | 2 × 2 × 7 × 23 |
| 19 | 682 | 2 | 42,966 | 2 × 11 × 31 |
| 20 | 720 | 18 | 5,040 | 2 × 2 × 2 × 2 × 3 × 3 × 5 |
Key Analytical Takeaways
- 01The shared prime factors in the overlap of $A$ and $B$ multiply to form $\gcd(A,B)$ (also called Highest Common Factor, HCF).
- 02Multiplying the shared $\gcd$ primes by the remaining unshared primes of both numbers yields $\text{lcm}(A,B)$.
- 03When $\gcd(A,B) = 1$, the two integers share no prime factors and are called coprime (relatively prime), so $\text{lcm}(A,B) = A \times B$.
Frequently Asked Questions
What is the difference between GCD, GCF, and HCF?+
Greatest Common Divisor (GCD), Greatest Common Factor (GCF), and Highest Common Factor (HCF) are three names for the exact same value: the largest positive integer that divides both A and B with zero remainder.
How is LCM used when adding fractions?+
The Least Common Denominator (LCD) of two fractions a/b and c/d is simply the LCM of their denominators b and d.
What does it mean when GCD(A, B) equals 1?+
When two integers share no common prime factors, their GCD is 1; they are called coprime (or relatively prime), and their least common multiple is simply their product A × B.