Know whether a number is power of two

There are several ways to find whether a given number is power of two. I am sharing two ways by which we can see if the number is power of two or not. There is a basic rule to know whether a given number is power of two or not. (N) & (N-1) is Zero. Here & is Bitwise and. When we use &, SQL server internally converts the given Number into Binary and performs Bitwise and. Take an example.
N=2 Binary is 10
N-1 = 1 Binary is 01
N& N-1 =
10
01
---
00
---
This is simple logic. This is the SQL code


DECLARE @N INT
SET @N =  -- pass a value
IF(@N & (@N-1))=0
PRINT 'Pow of two'
ELSE
PRINT 'Not pow of two'

The other way is to do it programatically. Here is how you can do



DECLARE @IncomingNumber int
SET @IncomingNumber = --pass a value
DECLARE @BinNumber VARCHAR(200)
SET @BinNumber = ''

WHILE @IncomingNumber <> 0
BEGIN

IF(@IncomingNumber%2 = 0)
SET @BinNumber = CAST(0 AS VARCHAR(200))+ @BinNumber
ELSE IF(@IncomingNumber%2=1)
SET @BinNumber= CAST(1 AS VARCHAR(200))+@BinNumber

SET @IncomingNumber = @IncomingNumber / 2

END

SELECT @BinNumber
IF(SUBSTRING(@BinNumber,1,1)=1 AND CAST(SUBSTRING(@BInNumber,2,LEN(@BinNumber)) AS INT) =0)
PRINT 'Pow of two'
ELSE
PRINT 'Not Pow of two'