GCF and LCM of 4 and 18
The greatest common factor and least common multiple of 4 and 18.
GCF of 4 and 18
2
LCM of 4 and 18
36
How it works
Break each number into its prime factors:
- 4 = 2²
- 18 = 2 × 3²
The GCF (2) multiplies the primes both share, at the lowest power each appears. The LCM (36) multiplies every prime that appears in either number, at the highest power — which is also 4 × 18 ÷ 2 = 36.
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Frequently asked questions
What is the GCF of 4 and 18?+
The greatest common factor (GCF) of 4 and 18 is 2 — the largest number that divides both 4 and 18 with no remainder.
What is the LCM of 4 and 18?+
The least common multiple (LCM) of 4 and 18 is 36 — the smallest number that both 4 and 18 divide into. It equals 4 × 18 ÷ GCF = 72 ÷ 2 = 36.