In the dystopian Netflix film “What Happened to Monday,” out Aug. 18, Swedish actress Noomi Rapace has the arduous task of playing seven sisters. The siblings, all named after days of the week, have to assume the identity of one person in order to survive in a society plagued by overpopulation. Things spiral out of control when one sister goes rogue. Rapace spoke with amNewYork about the challenges of playing seven different characters.

This is sci-fi but it doesn’t seem that far-fetched.

It was a bit of an eye-opener for me. I didn’t actually know how bad it was. When we were doing research and I started looking into all of this, I was quite shocked. It’s scary that so many world leaders are not taking [overpopulation] more seriously and working more aggressively to change things and prioritizing this. It’s not so far away. It’s a world that’s very close to us so it feels very real.

How challenging was it to play seven characters?

… Just having seven people living in me was extremely tough. They took over my life completely for five months. Normally, it’s a collaboration but in this one, I had to invent everything myself.

Did you relate to the sisters?

They’re almost based on me but just different types of me in my life. When I was a teenager, I was very much like Thursday. I was listening to punk rock and I was aggressive and explosive and had really strong opinions. Then I became more like Wednesday, working out all the time, like a tomboy, and there was a time where I was very introverted, too. I was more focused on studying people, like Friday.

How else did you chart their personalities?

I created a different playlist for each one of them. I had different perfumes for the sisters. Saturday had a very sweet vanilla-y and flowery perfume, she was listening to very girlie upbeat party music. Wednesday was listening to hip-hop and grime and her perfume was musky. Monday was only classical music and had a citric-y and neutral perfume.

Director Tommy Wirkola is known for his action films. Was the physicality easy to tap into?

It was really different. They all move differently so just to find six different ways of fighting. I had to go into each of their mindset and see from the inside to find how they move and fight. Then, I worked with the stunt coordinator to find different ways of fighting so it was extremely physical and I had to be very aware of my own body.

What do you make of the industry’s shift toward streaming platforms?

It’s changing and it’s happening. We can’t really fight it. If you look at the music industry, a lot of my friends are musicians and it hit them before it hit us. I embrace change. It’s quite amazing that people from all over the world will be able to see my film at the same time. . . . Though some movies deserve a big screen and to be theatrically released. We need to work and find a balance between that but we have to make the best out of it. It’s all for the love of film.