Cut substring between character I want to select the 3 numbers between ":". I don't know the length of this strings and the positions of the ":". I have as an example:

SELECT 'Espacio Asignado:358898204672: Espacio Usado:355976458989: Espacio Reclamable:2921745683:' FROM DUAL;


I think that with regexp, but I don't know how.
When you execute:

select total
from (SELECT regexp_substr('Espacio Asignado:358898204672: Espacio Usado:355976458989: Espacio Reclamable:2921745683:','[^:]+', 1, level) total
      FROM DUAL
      connect by regexp_substr('Espacio Asignado:358898204672: Espacio Usado:355976458989: Espacio Reclamable:2921745683:','[^:]+', 1, level) is not null)
where   REGEXP_LIKE(total, '^[[:digit:]]+$')
/


You get all the numeric values in the string.