e and pi are the only numbers I know to be transcendental, but sqrt(n) for any n not a perfect square is irrational but not transcendental.
The algebraic numbers have the same cardinality as integers. Consequently, since real numbers have a higher cardinality than integers and all real numbers are either algebraic or trancendental, trancendental numbers have a higher cardinality than algebraic ones. This despite the fact that between any two trancendental numbers there is at least one algebraic number.
Any number of the form Alpha^Beta is transcendental,
if Alpha and Beta are non-rational algebraic numbers.
This theorem was proven in 1926 by Gelfond.