GCF and LCM of 7 and 15
The greatest common factor and least common multiple of 7 and 15.
GCF of 7 and 15
1
LCM of 7 and 15
105
How it works
Break each number into its prime factors:
- 7 = 7
- 15 = 3 × 5
The GCF (1) multiplies the primes both share, at the lowest power each appears. The LCM (105) multiplies every prime that appears in either number, at the highest power — which is also 7 × 15 ÷ 1 = 105.
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Frequently asked questions
What is the GCF of 7 and 15?+
The greatest common factor (GCF) of 7 and 15 is 1 — the largest number that divides both 7 and 15 with no remainder.
What is the LCM of 7 and 15?+
The least common multiple (LCM) of 7 and 15 is 105 — the smallest number that both 7 and 15 divide into. It equals 7 × 15 ÷ GCF = 105 ÷ 1 = 105.