GCF and LCM of 11 and 22

The GCF of 11 and 22 is 11. The LCM of 11 and 22 is 22.

Method 1: list the factors (GCF)

Factors of 11: 1, 11.
Factors of 22: 1, 2, 11, 22.
Common factors: 1 and 11. The greatest of these is 11.

Method 2: prime factorization

11 = 11 (prime)
22 = 2 × 11

GCF: multiply the prime factors both numbers share: 11 = 11.

LCM: multiply every prime the maximum number of times it appears in either number: 2 × 11 = 22.

Method 3: Euclidean algorithm (GCF)

Divide the larger number by the smaller and repeat with the remainder until it is 0. The last non-zero remainder is the GCF.

  1. 22 = 2 × 11 + 0

The last non-zero remainder is 11, so GCF(11, 22) = 11.

LCM by listing multiples

Multiples of 11: 11, 22, 33, ...
Multiples of 22: 22, 44, ...
The first number in both lists is 22.

Check: GCF × LCM = product

11 × 22 = 242 = 11 × 22. This always holds for two numbers, so you can find the LCM as (11 × 22) ÷ 11 = 22.

Simplifying the fraction 11/22

Divide the top and bottom by the GCF 11: 11/22 = 1/2.

GCF and LCM of similar pairs

NumbersGCFLCM
2 and 11122
3 and 11133
4 and 11144
5 and 11155
6 and 11166
7 and 11177
2 and 22222
3 and 22166
4 and 22244
5 and 221110
6 and 22266
7 and 221154

See also: factors of 11 · factors of 22.

Different numbers? Use the GCF and LCM calculator (any amount of numbers) or browse all GCF and LCM pairs.