Show Minecraft Seed?

I found a village in Minecraft that I would like to edit in creative mode, but I also want to use the world for survival. When I created the world, I entered a random seed. Is there a way to view the seed so I can use it for a new world? Or is there another way to copy the world.

Simply enter / seed in the chat.

If necessary, briefly open the world in the Lan and activate cheats.