The work you have done on the penny is the amount of gravitational potential energy it has when it reaches the top.
Gravitational PE  =  (weight) x (height)
                               = (0.025 N) x (449 m)
                                =      11.225 joules  .
That's about the same amount of work it takes to carry 
one pound of butter to the top of an 8.5-foot ladder.