BOSTON (AP) — Secretary of State William Galvin’s office is confirming that 4.1 million Massachusetts residents have registered to vote in the state primary election.

Galvin’s office announced Tuesday that of those registered to vote in the Sept. 6 primary, more than 35 percent are registered as Democrats while more than 11 percent are registered as Republicans.

Nearly 53 percent of those registered were unenrolled. The deadline to register was Aug. 17.

Barnstable County had the highest proportion of Republicans registered at more than 16 percent. Suffolk County had the highest percentage of Democrats registered, at nearly 54 percent.

Massachusetts voters who registered for the September primary will be able to vote on some statewide, congressional district, state Legislature and local races.