The Real Academia de la Lengua Española (Royal Academy of Spanish Language) prohibits the use of commas as separators within numbers for every factor of 1000, since the comma is used as decimal separator. For example, what in English is written as 1,000,000.54, we write it as 1000000,54.
However, it is also required that a small space be used as separator (something like
$1\,000\,000.54$). I would like to know how to do this automatically in LaTeX (possibly with babel). I could do it manually, but I have already written too many numbers, and some come from software that don't take into account these rules.
Thanks in advance for your answers!