Prefix '0' with Numbers

In most of the scenario, we need to prefix '0' (Zero) with numbers.

If my result is 15 then, it should be resulted as 00015
If my result is 2010 then, it should be resulted as 02010

So, the total length should be 5.

If the total length is 5 then '0' should be prefixed based on the result.

Input	Result
1	00001
15	00015
151	00151
1515	01515
15151	15151

IF OBJECT_ID('[DBO].[UFN_PrefixZero]','FN') IS NOT NULL
DROP FUNCTION [DBO].[UFN_PrefixZero]
GO
CREATE FUNCTION [DBO].[UFN_PrefixZero](@Input VARCHAR(10),@TotalLength INT) RETURNS VARCHAR(MAX) AS
BEGIN
	RETURN ISNULL(REPLICATE('0',@TotalLength - LEN(@Input)),'') + @Input
END
GO

Input is 45, Total length is 5

SELECT [DBO].UFN_PrefixZero(45,5)
GO

Result Is: 00045

Input is 45, Total length is 10

SELECT [DBO].UFN_PrefixZero(45,10)
GO

Result Is: 0000000045

Input is 45, Total length is 20

SELECT [DBO].UFN_PrefixZero(45,20)
GO

Result Is: 00000000000000000045

Input is 45, Total length is 50

SELECT [DBO].UFN_PrefixZero(45,50)
GO

Result Is: 00000000000000000000000000000000000000000000000045