DECLARE @number INT = 500;

SELECT (SELECT N 
        FROM (SELECT TOP (LEN(@number))
              SUBSTRING(CAST(@number AS VARCHAR(19)),N,1)
              FROM (VALUES(1),(2),(3),(4),(5),(6),(7),(8),(9),
                          (10),(11),(12),(13),(14),(15),(16),(17),
                          (18),(19))a(N)
              WHERE N <= (LEN(@number))
              ORDER BY N DESC) b(N)
        FOR XML PATH(''), TYPE).value('.', 'VARCHAR(19)');

DECLARE @number INT = 500;

SELECT (SELECT N 
        FROM (SELECT TOP (LEN(@number))
              SUBSTRING(CAST(@number AS VARCHAR(19)),N,1)
              FROM (VALUES(1),(2),(3),(4),(5),(6),(7),(8),(9),
                          (10),(11),(12),(13),(14),(15),(16),(17),
                          (18),(19))a(N)
              WHERE N <= (LEN(@number))
              ORDER BY N DESC) b(N)
        FOR XML PATH(''), TYPE).value('.', 'VARCHAR(19)');

SELECT Num = (
	SELECT SUBSTRING(x.NumAsString,tally.n,1)
	FROM (SELECT 123456789012335.782) MyValue (mynumber)
	CROSS APPLY (SELECT CAST(MyValue.mynumber AS VARCHAR(19))) x (NumAsString) 
	CROSS APPLY(
		SELECT TOP (DATALENGTH(x.NumAsString)) n
		FROM (SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL 
			SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9 UNION ALL SELECT 10 UNION ALL
			SELECT 11 UNION ALL SELECT 12 UNION ALL SELECT 13 UNION ALL SELECT 14 UNION ALL SELECT 15 UNION ALL
			SELECT 16 UNION ALL SELECT 17 UNION ALL SELECT 18 UNION ALL SELECT 19) t (n)
	) tally (n)
	ORDER BY n DESC
	FOR XML PATH(''),type).value('.','varchar(max)')

DECLARE @Number Float
SET @Number = 1234.56

--   Create a string version of the number
DECLARE @Number_String VarChar(250)
SET @Number_String = CONVERT(VarChar(250), @Number);

--  Create a "Common Table Expression" with numbers 0-9 as rows.
WITH Base (Digit) AS 
	(
		SELECT 0 UNION ALL
		SELECT 1 UNION ALL
		SELECT 2 UNION ALL
		SELECT 3 UNION ALL
		SELECT 4 UNION ALL
		SELECT 5 UNION ALL
		SELECT 6 UNION ALL
		SELECT 7 UNION ALL
		SELECT 8 UNION ALL
		SELECT 9 
	)
--  Re-assemble the characters in the reverse order.
SELECT 
	IsNull(MAX(CASE Backwards.Position WHEN 10 THEN Backwards.Number ELSE Null END),'') + 
	IsNull(MAX(CASE Backwards.Position WHEN  9 THEN Backwards.Number ELSE Null END),'') + 
	IsNull(MAX(CASE Backwards.Position WHEN  8 THEN Backwards.Number ELSE Null END),'') + 
	IsNull(MAX(CASE Backwards.Position WHEN  7 THEN Backwards.Number ELSE Null END),'') + 
	IsNull(MAX(CASE Backwards.Position WHEN  6 THEN Backwards.Number ELSE Null END),'') + 
	IsNull(MAX(CASE Backwards.Position WHEN  5 THEN Backwards.Number ELSE Null END),'') + 
	IsNull(MAX(CASE Backwards.Position WHEN  4 THEN Backwards.Number ELSE Null END),'') + 
	IsNull(MAX(CASE Backwards.Position WHEN  3 THEN Backwards.Number ELSE Null END),'') + 
	IsNull(MAX(CASE Backwards.Position WHEN  2 THEN Backwards.Number ELSE Null END),'') + 
	IsNull(MAX(CASE Backwards.Position WHEN  1 THEN Backwards.Number ELSE Null END),'') AS Reverse_Number
FROM 
	(
		SELECT 

			--  Select a substring from the current number character position
			SUBSTRING(@Number_String, All_Numbers.Number, 1) AS Number,

			--  The position the substring started at...
			All_Numbers.Number AS Position

		FROM 
			(
			-- Create a table query with numbers 1-100,000 as rows
			-- by joining the Base table once for each decimal place...
				SELECT 
					D5.Digit * 10000 + 
					D4.Digit * 1000  +
					D3.Digit * 100   + 
					D2.Digit * 10    + 
					D1.Digit + 1     AS Number
				FROM 
					Base D1 CROSS JOIN
					Base D2 CROSS JOIN
					Base D3 CROSS JOIN
					Base D4 CROSS JOIN
					Base D5 
			) All_Numbers
		WHERE 
			--  Filter off any numbers greater than the length of the string.
			All_Numbers.Number <= LEN(@Number_String)
	) Backwards

DECLARE @num INT = 102948092

DECLARE @numstr VARCHAR(10)
SET @numstr = @num

DECLARE @tab TABLE(
num INT,
numc CHAR(1))

;WITH
 t1 AS (SELECT 1 N UNION ALL SELECT 1 N),
 t2 AS (SELECT 1 N FROM t1 x, t1 y),     
 t3 AS (SELECT 1 N FROM t2 x, t2 y),     
 t4 AS (SELECT 1 N FROM t3 x, t3 y),     
 t5 AS (SELECT 1 N FROM t4 x, t4 y),     
 Tally AS (SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) N
 FROM t3 x, t3 y)
INSERT @tab
SELECT
N,
SUBSTRING(@numstr,N,1)
FROM 
tally
WHERE
N <= LEN(@numstr)


SELECT
@num,
newstr = REPLACE(REPLACE(CAST((SELECT numc FROM @tab ORDER BY num desc FOR XML PATH('')) AS varchar(MAX)),'<numc>',''),'</numc>','')

SELECT *
FROM (VALUES(1),(2),(3),(4),(5),(6),(7),(8),(9),
            (10),(11),(12),(13),(14),(15),(16),(17),
            (18),(19)
      )a --Alias for the values constructor
      (N) --Column name for the data in the values constructor
;

N
-----------
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19

DECLARE @number INT = 500;
        
SELECT b.N
FROM (SELECT TOP (LEN(@number))
      SUBSTRING(CAST(@number AS VARCHAR(19)),a.N,1)
      FROM (VALUES(1),(2),(3),(4),(5),(6),(7),(8),(9),
                  (10),(11),(12),(13),(14),(15),(16),(17),
                  (18),(19)
            )a --Alias for the values constructor
            (N) --Column name for the data in the values constructor
      WHERE a.N <= (LEN(@number))
      ORDER BY a.N DESC
      ) b --Alias for the inner query
      (N) --Column name for the data in the inner query
;

N
----
0
0
5

DECLARE @number INT = 500;
        
SELECT b.N
FROM (SELECT TOP (LEN(@number))
      SUBSTRING(CAST(@number AS VARCHAR(19)),a.N,1)
      FROM (VALUES(1),(2),(3),(4),(5),(6),(7),(8),(9),
                  (10),(11),(12),(13),(14),(15),(16),(17),
                  (18),(19)
            )a --Alias for the values constructor
            (N) --Column name for the data in the values constructor
      WHERE a.N <= (LEN(@number))
      ORDER BY a.N DESC
      ) b --Alias for the inner query
      (N) --Column name for the data in the inner query
FOR XML PATH(''), TYPE;

-------------------------
<N>0</N><N>0</N><N>5</N>

DECLARE @number INT = 500;
        
SELECT (SELECT b.N
        FROM (SELECT TOP (LEN(@number))
              SUBSTRING(CAST(@number AS VARCHAR(19)),a.N,1)
              FROM (VALUES(1),(2),(3),(4),(5),(6),(7),(8),(9),
                          (10),(11),(12),(13),(14),(15),(16),(17),
                          (18),(19)
                    )a --Alias for the values constructor
                    (N) --Column name for the data in the values constructor
              WHERE a.N <= (LEN(@number))
              ORDER BY a.N DESC
              ) b --Alias for the inner query
              (N) --Column name for the data in the inner query
        FOR XML PATH(''), TYPE
        ).value('.', 'VARCHAR(19)');

-------------------
005