In the world, Dullen (Dullen 
) is an extremely rare dominantly boy's, but infrequently girly first name. Much more prevalently, Dullen is the last name as well as the forename.
Ali, Jill, Tara, Eric, Emma, Earl, Mario, Sarah, Shawn, Alice, Arlin, Amber, Aaron, Chris, Carol, Brian, Karen, Kenyu, Kelly, Keith, Randy, Ricky, Jean, Devon, Jenn, Josh, Coy, Bob, Rod, Roy, Deb, Lee, Luz, Jon, Tom, Marc, Mary, Mark, Mila, Anna, Bill, Paul, Rick, Rita, Ryan, Dana, Dawn, John, and Derek