The sales sum also sparks the cut's No. 1 debut on Rock Digital Song Sales, marking each artist's first leader. Sheeran is the only member of the trio with a prior history on the tally, having reached a previous No. 3 best with "Lego House" in 2013.
While country/Americana titan Stapleton and pop/R&B superstar Mars make their maiden Hot Rock Songs visits, Sheeran appears for the first time since, again, 2013, after which he segued more toward pop.
"Blow" also bows at No. 40 on the Mainstream Rock Songs airplay chart, a first for Sheeran and Mars; Stapleton's "Midnight Train to Memphis" hit No. 26 in March 2018.
On the all-format, streaming-, airplay- and sales-based Billboard Hot 100 (the same formula employed by Hot Rock Songs), "Blow" begins at No. 60.
No.6 Collaborations Project is aiming for a lofty launch on next week's Billboard 200, dated July 27. The album features other genre-bending songs, with Sheeran veering into hip-hop and Latin touches alongside his core pop sound.