GCF and LCM of 9 and 18
The greatest common factor and least common multiple of 9 and 18.
GCF of 9 and 18
9
LCM of 9 and 18
18
How it works
Break each number into its prime factors:
- 9 = 3²
- 18 = 2 × 3²
The GCF (9) multiplies the primes both share, at the lowest power each appears. The LCM (18) multiplies every prime that appears in either number, at the highest power — which is also 9 × 18 ÷ 9 = 18.
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Frequently asked questions
What is the GCF of 9 and 18?+
The greatest common factor (GCF) of 9 and 18 is 9 — the largest number that divides both 9 and 18 with no remainder.
What is the LCM of 9 and 18?+
The least common multiple (LCM) of 9 and 18 is 18 — the smallest number that both 9 and 18 divide into. It equals 9 × 18 ÷ GCF = 162 ÷ 9 = 18.