Here's a couple of ideas.
DECLARE @Now DATETIME
SET @Now = GETDATE()
SELECT @Now
SELECT CAST(datepart(yy, @Now) AS CHAR(4)) +
RIGHT('0'+LTRIM(cast(datepart(mm, @Now) as VARCHAR(2))), 2) +
RIGHT('0'+LTRIM(cast(datepart(dd, @Now) as VARCHAR(2))), 2) +
RIGHT('0'+LTRIM(cast(datepart(hh, @Now) as VARCHAR(2))), 2) +
RIGHT('0'+LTRIM(cast(datepart(mm, @Now) as VARCHAR(2))), 2) +
RIGHT('0'+LTRIM(cast(datepart(ss, @Now) as VARCHAR(2))), 2) +
RIGHT('00'+LTRIM(cast(datepart(ms, @Now) as VARCHAR(3))), 3)
SELECT REPLACE(REPLACE(REPLACE(REPLACE(CONVERT(VARCHAR(28), @Now, 121), '-', ''), ' ', ''), ':', ''), '.', '')
For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden