Since this planet takes so much longer than Earth does to go around its star, I'm assuming the star will be brighter than the Sun, since the planet will have to be farther away. So it won't be a star like our Sun: it will be either a larger, brighter main-sequence star or a star originally like our Sun that has turned into a red giant.
Having such long nights and days means that the planet is almost as good as tide-locked. The planet will need a dense atmosphere to act as a buffer, preventing temperature extremes. An atmosphere can shield the planet from the sun's heat during the day and keep the heat when the sun goes down.
Water is also a very efficient temperature moderator. Oceans and lakes can absorb heat slowly during the day and then radiate it again during the night. Water also evaporates forming clouds that reflect sunlight back to space.
I remember reading of a science fiction story in which most animals coped with a situation like this by migrating continuously, following the sun. The worst place to do this would be the equator, since that's where the planet rotates the fastest. If your planet is a bit larger than Earth (say, with an equatorial circumpherence of 50000 km) and it rotates once every 500 Earth days, then an animal that wanted to stay all the time under the sun would have to move at a rate of 100 km per day along the equator. Even that is not too much, actually (some large Earth animals often travel that distance in a day looking for food).
As for plants and slower animals, maybe they could do what many Earth organisms do: lie low and hibernate during the night, wake up and reproduce during the day.
As for humans, maybe we could develop a mixture of these strategies. We could be engineered to be able to "shut down" and hibernate, or develop a nomadic civilization.