This number is a prime.
377 7893186295 7154241011
The largest known Honaker prime, as of August 27, 2009. Note that 37778931862957154241011 is the 741263521140739969679th prime and each number contains the same sum of digits. Tomás Oliveira e Silva's computation of π(275) was used to achieve this result. See current record. [Andersen]