Convert exponential to number in sql

Try to cast your string to float before converting it :

SELECT CONVERT(numeric(16,0), CAST(TOKEN AS FLOAT))
FROM MULTICURRENCY_CHECK

• See this fiddle.

I don't know what's the format of those numbers in your XML source, but with the data you provide, you'll end up with 33733 for instance followed by a bunch of zeroes. If you have a bigger precision in your XML, maybe you should tweak your importing settings to keep this precision instead of trying to deal with that in the DB.

EDIT:

Try testing your strings with ISNUMERIC to avoid the casting errors you're getting. Adding a raw output of your column will allow you to check which value fails to convert (i.e. converts to 0).

SELECT TOKEN, 
       CONVERT(NUMERIC(16, 0), CAST(CASE 
                                      WHEN ISNUMERIC(TOKEN) = 1
                                      THEN TOKEN 
                                      ELSE 0 
                                    END AS FLOAT)) 
FROM   MULTICURRENCY_CHECK