This notation is common in Physics. The 1972 Nemeth code book has the answer in section 11.c. "The numeric indicator must not be used after a space if the purpose of the space is to partition a numeral into segments." The new (forthcoming) code will not be changing this rule, but in UEB with Nemeth you do need to observe the following details: transcribe a partitioned number in Nemeth; keep the number all together on one line as well as on the same line as the associated abbreviation (in this case, "m").
If the number is too long to fit on one braille line, use as much of the line as you can and then start the runover line with the next segment. Do not insert a hyphen and do not use a numeric indicator at the beginning of the runover line. That would give the wrong impression that it is a new number, which it is not.
Here is how your example will be transcribed in UEB with Nemeth.
,! 4T.E F ,E>? TO ! SUN IS
_% #149 600 000 000 ;M _:4