Skewes' number is not an integer.
Skewes, S. (1933), "On the difference ", Journal of the London Mathematical Society 8: 277–283
Assuming Schanuel's conjecture, one can show that e^e^e^79 is transcendental.
Schanuel's conjecture
Assuming Schanuel's conjecture, one can show that e^e^e^79 is transcendental.