9^9^9 in 33 volumes (published 6 Jan 2004):

9^9^9 has: 369693100 digits

Volume 01: 11000000 digits

Volume 02: 11000000 digits

Volume 03: 11000000 digits

Volume 04: 11000000 digits

Volume 05: 12000000 digits

Volume 06: 11000000 digits

Volume 07: 11000000 digits

Volume 08: 11000000 digits

Volume 09: 11000000 digits

Volume 10: 12000000 digits

Volume 11: 11000000 digits

Volume 12: 11000000 digits

Volume 13: 11000000 digits

Volume 14: 11000000 digits

Volume 15: 12000000 digits

Volume 16: 11000000 digits

Volume 17: 11000000 digits

Volume 18: 11000000 digits

Volume 19: 11000000 digits

Volume 20: 12000000 digits

Volume 21: 11000000 digits

Volume 22: 11000000 digits

Volume 23: 11000000 digits

Volume 24: 11000000 digits

Volume 25: 12000000 digits

Volume 26: 11000000 digits

Volume 27: 11000000 digits

Volume 28: 11000000 digits

Volume 29: 11000000 digits

Volume 30: 12000000 digits

Volume 31: 11000000 digits

Volume 32: 11000000 digits

Volume 33: 11693100 digits