That's the famous pi as in Π. (I think it should have curly bits but the standard HTML character doesn't show any.)
Fabrice Bellard has just calculated this constant to
2699999999999
decimal places, using only a PC, see
This is a new record, for any computer.
The result occupies a bit over 1 TB (that's 10 Olympic swimming pools). I think you will not want to download it all. Parts of it are available
This is certainly a triumph of human ingenuity and spirit. But it's hard to say whether all the effort that goes into any sort of record-breaking is worth it or not. I'd be really glad to know other people's views on this one.