The trouble is that you have stored your numer as a string - so it uses a strign comparision for everything, and that works on a character-by-character basis. The firts character that is differnet decides the comparison.
The best solution is never to store numeric data as strings; use a numeric field. That way comparisons work properly, and you can useful things like math operations on them.
Failing that, you'd need to convert the strign to an number - and hope like heck that none of them contain "bad" characters...
...ORDER BY CAST(radif AS INT) ASC
Will do it temporarily, but seriously - change your DB!