Let the three numbers be \( 2x \), \( 3x \), and \( 4x \). The sum of these numbers is given as 270:
\[
2x + 3x + 4x = 270 \quad \Rightarrow \quad 9x = 270 \quad \Rightarrow \quad x = 30.
\]
So, the numbers are \( 2x = 60 \), \( 3x = 90 \), and \( 4x = 120 \).
Now, the L.C.M. of 60, 90, and 120 is:
\[
\text{L.C.M.} = 360.
\]