Solomon Rutzky (7/27/2013)
23847234872893475983479583749583749573945739 is all digits, is a valid number, but is NOT convertible to any SQL Server number types as it is larger than 38 digits ...
You can convert it to float (with lose of some precision ;-))
select cast('23847234872893475983479583749583749573945739' as float)