If each ticket was $1 and then there are 21 million unique numbers, then on average there are 6.5 people per draw.

Also in any case someone buying one of everything vs buying randomly the same amount wouldn't affect the expected return of anyone.

The jackpot rolled over multiple times without a winner, except in this case many more rollovers than the average. As the article mentions, typically there were only "one or two million tickets [purchased] on each draw."