Is there a database agnostic way to perform an ISNUMERIC check in a query?

Question

I have a query like below. I may be switching between SQL Server, Oracle etc. Is there a database agnostic way to perform an ISNUMERIC check in a query?

SELECT name 
FROM Students 
WHERE ISNUMERIC(columnName) = 0

I tried using REGEXP_LIKE and similar things but they all favour certain DB types and not others.