What is the LCM of 126 266 and 38?

The LCM of 126, 266, and 38 is $\boxed{ 19 794 }$.

Prime factorizations:

$$126=2\cdot3^2\cdot7$$

$$266=2\cdot11\cdot13$$

$$38=2\cdot19$$

To find the LCM:

$$LCM(126,226,38) = 2^2\cdot 3^2\cdot 7 \cdot 11 \cdot 13 \cdot 19$$

$$LCM(126,266,38) = 19 794$$