Conversion Failed When Converting The Nvarchar...

One of my clients decided to put letters into their customers' account numbers. They have a numbering scheme where all temporary accounts have a letter in the account OR are numbered greater than 33000, and all permanent accounts are all digits and less than or equal to 33000. all primary accounts have a NumberSuffix of 000.

Now i am tasked with retrieving all primary, non-temp accounts. I cannot simply do WHERE Number <= 33000 because when it gets to an account containing a letter like "00A01", it craps out and says "Conversion failed when converting the nvarchar value '00A01' to data type int."

So decided to run a filtering query first to filter out all accounts with letters, and then from that dataset select all accounts <=33000.

WITH members (FirstName, LastName, Number, NumberSuffix) AS
(
SELECT
dbo.Entity.FirstName,
dbo.Entity.LastName,
dbo.Entity.Number,
dbo.Entity.NumberSuffix
FROM
dbo.Entity
WHERE
NumberSuffix = 000 AND
Number NOT LIKE '%A%' AND
Number NOT LIKE '%B%' AND
Number NOT LIKE '%C%' AND
Number NOT LIKE '%D%' AND
Number NOT LIKE '%E%' AND
Number NOT LIKE '%F%' AND
Number NOT LIKE '%G%' AND
Number NOT LIKE '%H%' AND
Number NOT LIKE '%I%' AND
Number NOT LIKE '%J%'
)
SELECT *
FROM
members
WHERE
Number <= 33000
ORDER BY
Number
when i do this, i get the same error for some reason. Yet when i execute this at the end instead:
SELECT *
FROM
members
WHERE
Number LIKE '%A%'
ORDER BY
Number
i get an empty set (meaning it actually does get filtered).
but somehow it still able to participate in a range comparison?

WHY??

thanks,
Leon