For the "before 1000" years, I probably say "five twenty-six" more often than "five hudred twenty-six." But you may hear either. Sometimes for those "early years" you'll hear "A.D." thrown in, but that's obviously not required.
For four-digit number, I would indeed say "eighty-six fifty-three."
Since I do have to work with charts and sometimes it's easier to have two people proofread, here's what I might say:
Sixteen (slight pause) three eighty-four. I might say "thousand" instead of the pause.
One hundred twenty five thousand, four sixty one. Actually, since it's probably numbers in a chart "one twenty five comma four sixty one"
One million, two hundred eighty-nine thousand, one twenty-one.