The number is supposed to be 854k in the US according to this article : https://www.theverge.com/2021/11/12/22776640/nintendo-switch-oled-sales-october-2021-doug-bowser-interview

Outside of hardware, Nintendo noted that Metroid Dread — which launched alongside the OLED Switch on October 8th — sold 854,000 units in the US, making it “the best start for any Metroid game ever,” according to Bowser. Meanwhile, Animal Crossing: New Horizons received “a significant spike in people buying the game” after its final major update, according to Nintendo, though the company hasn’t released specific numbers on this. New Horizons is currently the second best-selling Switch game with nearly 35 million units sold globally.

So in just over three weeks, in a single country, and not including digital, it's sold nearly a third of the current highest selling Metroid game's total.

Globally and overall, it's probably well over half of Prime by the end of last month. I think it's safe to say at this point that the ceiling for Metroid sales is going to be shattered.

Basing these off of Paul Gale's calculations, these could be Dread's final sales figures if they follow these stats.

854k x 3.62 = 3,091,480 units in the US alone.

3,091,480 / .55 = 5,620,873 units worldwide.

I'm shaking from excitement. That's insane. And I thought 3.5mil was the ceiling before it launched. Since it has great wom it's launch to lifetime multiplier could be way better than the 3.62 average.

We don't have the complete picture yet, only Japan numbers and October numbers in the US, the former physical only. I'm gonna withhold judgement til we get the next quarterly report, but I think all things considered it seems to be off to a very strong start. This isn't Mario or Zelda after all, Metroid has always been comparatively niche.

What exactly were you expecting, if I may ask?

Because by Metroid's standards, this is absolutely fantastic. Any Metroid fan should be overjoyed by those numbers. It's at an easy 1 million between the US and Japan alone. If we factor in Europe and the rest of the other regions, it's probably closing in on Prime 1 as we speak.

Great news regarding the sales of Metroid Dread!! We'll definitely see more Metroid games soon, including Prime 4.

The US number does include digital. We know that.

5mil+ is now almost guaranteed. No need to be disappointed.

Metroid Dread, a 2D $60 game in 2021, has a first month sales total in the US that is greater than Metroid Prime 1, Prime 2, Prime 3, and Prime Trilogy's combined first month total. The fact that Nintendo made point to highlight it's sales numbers speaks volumes. Fire Emblem Three House ended up at over 3 million lifetime. Nintendo didn't announce it's first month's sales totals. Hell, Fire Emblem fans had to wait for a quarterly report to see the game was doing well.

Over 5 million lifetime is definitely on the table, but honestly just selling over 3 million would be a big deal for a series that in 35 years and 14 entries has never hit that threshold, and has only passed 2 million twice.
If Dread ends up selling say, 3.5 or 4 million, I'd consider that a success and be satisfied.