More than 16 Republicans running for president

Washington Post - There are more than 16 Republicans running. Already. Right now. As of earlier this week, there are more than a hundred Republican presidential candidates, joining 73 Democrats and a staggering 266 candidates who affiliate with no party or a third party.

Taken literally, nearly 2,500 people have run for president since 1980, in the sense that they filled out the requisite form with the Federal Election Commission (which is remarkably trivial to do). Since many have run multiple times, it's a grand total of more than 3,100 separate candidacies.

For elections that have produced a total of five different presidents.