Help With TSQL Stored Procedure - Error-Exec Point-Procedure Code

I am building a stored procedure that changes based on the data that is available to the query. See below.
The query fails on line 24, I have the line highlighted like this.
Can anyone point out any problems with the sql?

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This is the error...


Msg 8114, Level 16, State 5, Procedure sp_SearchCandidatesAdvanced, Line 24

Error converting data type varchar to numeric.

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This is the exec point...


EXEC [dbo].[sp_SearchCandidatesAdvanced]

@LicenseType = 4,

@PositionType = 4,

@BeginAvailableDate = '10/10/2006',

@EndAvailableDate = '10/31/2007',

@EmployerLatitude = 29.346675,

@EmployerLongitude = -89.42251,

@Radius = 50

GO

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This is the STORED PROCEDURE...


set ANSI_NULLS ON

set QUOTED_IDENTIFIER ON

go



ALTER PROCEDURE [dbo].[sp_SearchCandidatesAdvanced]

@LicenseType int = 0,

@PositionType int = 0,

@BeginAvailableDate DATETIME = NULL,

@EndAvailableDate DATETIME = NULL,

@EmployerLatitude DECIMAL(10, 6),

@EmployerLongitude DECIMAL(10, 6),

@Radius INT


AS


SET NOCOUNT ON


DECLARE @v_SQL NVARCHAR(2000)

DECLARE @v_RadiusMath NVARCHAR(1000)

DECLARE @earthRadius DECIMAL(10, 6)


SET @earthRadius = 3963.191


-- SET @EmployerLatitude = 29.346675

-- SET @EmployerLongitude = -89.42251

-- SET @radius = 50


SET @v_RadiusMath = 'ACOS((SIN(PI() * ' + @EmployerLatitude + ' / 180 ) * SIN(PI() * p.CurrentLatitude / 180)) + (COS(PI() * ' + @EmployerLatitude + ' / 180) * COS(PI() * p.CurrentLatitude / 180) * COS(PI()* p.CurrentLongitude / 180 - PI() * ' + @EmployerLongitude + ' / 180))) * ' + @earthRadius




SELECT @v_SQL = 'SELECT p.*, p.CurrentLatitude, p.CurrentLongitude, ' +

'Round(' + @v_RadiusMath + ', 0) AS Distance ' +

'FROM ProfileTable_1 p INNER JOIN CandidateSchedule c on p.UserId = c.UserId ' +

'WHERE ' + @v_RadiusMath + ' <= ' + @Radius


IF @LicenseType <> 0

BEGIN

SELECT @v_SQL = @v_SQL + ' AND LicenseTypeId = ' + @LicenseType

END


IF @PositionType <> 0

BEGIN

SELECT @v_SQL = @v_SQL + ' AND Position = ' + @PositionType

END


IF LEN(@BeginAvailableDate) > 0

BEGIN

SELECT @v_SQL = @v_SQL + ' AND Date BETWEEN ' + @BeginAvailableDate + ' AND ' + @EndAvailableDate

END


--SELECT @v_SQL = @v_SQL + 'ORDER BY CandidateSubscriptionEmployerId DESC, CandidateFavoritesEmployerId DESC, Distance'


PRINT(@v_SQL)

EXEC(@v_SQL)


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