If you want to count the number that exceeds the maximum value of INT datatype, you can make use of COUNT_BIG function. COUNT_BIG function always returns a bingint datatype value. Consider the following example code which uses both COUNT_BIG and COUNT function

select COUNT_BIG(*) as big_number, COUNT(*) as number into #t

select * from #t

Now execute this code to see the datatypes of these columns

select 
	c.name as column_name, t.name as data_type 
from 
	tempdb..syscolumns as c inner join tempdb..systypes as t
on c.xtype=t.xtype 
where 
	id=OBJECT_ID('tempdb..#t')
	

The result is

column_name           data_type
-----------------     ----------
number                int
big_number            bigint

Note that the big_number column has a datatype of bigint and if you have want to count rows with more than 2147483647 rows you can use that function