Declare @phoneNumber int
select @phoneNumber=Isnull('08041159620',0);
Give error :
The conversion of the varchar value '8041159620' overflowed an int column.: select cast('8041159620' as int)
AS
Integer is defined as :
Integer (whole number) data from -2^31 (-2,147,483,648) through 2^31 - 1 (2,147,483,647). Storage size is 4 bytes. The SQL-92 synonym for int is integer.
Solution
Declare @phoneNumber bigint