The number is six.

This is Week 6 of the college football season. The top six teams in the preseason Associated Press Top 25 are still the top six teams, although not in the same order.

There haven’t been any upsets among the six although Clemson came mighty close to being knocked off last week at North Carolina. Don’t expect any surprises this week; the AP reports the top six — Alabama, Clemson, Georgia, Ohio State, Louisiana State, Oklahoma — are favored Saturday by an average of 26 ½ points.

In all, 18 unbeaten FBS teams remain, with five each in the SEC and the Big Ten. One game Saturday matches a pair of unbeaten teams.

No. 7 Auburn at No. 10 Florida, 3:30 p.m., CBS3

At this time last year, you can bet neither Bo Nix nor Kyle Trask expected to be quarterbacking an undefeated top 10 team looking to stay in playoff contention. Now they’ll be in the spotlight in Gainesville in the first meeting of the two teams since 2011.

Nix, a true freshman, has really settled in. After completing 47% of his passes in Auburn’s first two games, he has thrown at a 70% rate in his last three, including a 335-yard performance last week against Mississippi State.

Trask hadn’t started a game since his freshman year of high school before taking over last month for the injured Feleipe Franks at Florida. The junior has completed better than 77% of his passes (fourth nationally) for 647 yards and five touchdowns.

With the Gators’ offensive line struggling, the Tigers likely will get pressure on Trask from defensive linemen Marlon Davidson and Derrick Brown. Every little advantage helps, especially considering each team has games remaining against No. 3 Georgia and No. 5 Louisiana State.

No. 14 Iowa at No. 19 Michigan, noon, Fox29

After an unimpressive first three games, the Wolverines gained some confidence last week even if it meant beating up on poor old Rutgers. Knocking off the Hawkeyes, however, could propel them back in the conversation for the Big Ten East title.

Iowa, meanwhile, wants to keep up with Wisconsin and Minnesota and remain undefeated in the West. The Hawkeyes rushed for 351 yards last week against Middle Tennessee and are getting fine play from quarterback Nathan Stanley, who has a streak of 136 consecutive passes without an interception going back to last season.

Iowa, which hosts Penn State next week, could want to emphasize the run again since Michigan gave up 359 yards on the ground to Wisconsin a few weeks ago. Turnovers could be also be a key: Iowa has just one thus far, and the Wolverines have 10.

No. 3 Georgia at Tennessee, 7 p.m., ESPN

Bulldogs quarterback Jake Fromm says he got introduced to “big-boy football” in college by Jim Chaney, the Volunteers’ offensive coordinator who once held the same position at Georgia.

Fromm, now a junior, has taken the lessons and run with them, completing nearly 76% of his passes for 788 yards and six touchdowns with no interceptions. Georgia’s featured offensive threat is D’Andre Swift (St. Joseph’s Prep), who is eighth in FBS with a 7.92-yard-per-carry average.

The Vols are in a rebuilding phase but have played decent defense and have a pass-catching threat in senior Jauan Jennings, who has snared 19 passes for 298 yards and four touchdowns.

No. 25 Michigan State at No. 4 Ohio State, 7:30 p.m., 6ABC

The Spartans have built a reputation under Mark Dantonio for strong defense and this year is no exception – fourth in the nation in rushing defense, seventh in total defense, plus-6 in turnover margin.

The question is, can they stop a Buckeyes offensive juggernaut that has won its last four games by at least 41 points each, including last weekend’s 48-7 rout of Nebraska? Quarterback Justin Fields has 16 touchdown passes and seven TD runs for a team that averages more than 52 points and 535 yards per game.

Baylor at Kansas State, 3:30 p.m., ESPN2

It was a good week for former Temple head coach Matt Rhule, who was given a contract extension at Baylor that keeps him there as head coach through the 2027 season. After an 8-17 record in his first two years, Rhule has led the Bears to a 4-0 record in 2019. And here’s a stat that goes back to his days with the Owls: he has won 36 consecutive games when his team begins the fourth quarter with the lead.

California at No. 13 Oregon, 8 p.m., Fox29

With Cal’s loss last weekend, the Pac-12 became the first Power 5 conference -- already -- without a single undefeated team. Does that mean the league is weak? Or does it mean it has incredible parity? More importantly, does this lock the Pac-12 out of the College Football Playoff? With seven one-loss teams, including these two, the conference will need a member to get hot to stay in the race.

What else is happening?

- No. 6 Oklahoma might have the best tandem of wide receivers in the nation in sophomore Charleston Rambo (28.7 yards per catch) and junior CeeDee Lamb (25.9 yards per catch), both benefiting from the talent of Jalen Hurts. Les Miles and his Kansas Jayhawks will see their secondary stretched thin.

- No. 15 Washington scored 15 points off three USC turnovers last weekend and has six touchdowns and a field goal off turnovers for the season. Quarterback Jacob Eason will lead the Huskies into Stanford in a Pac-12 North clash.

- After being outscored last week by a combined 111-0, Maryland and Rutgers will meet in Piscataway in what will be the first game for Scarlet Knights interim head coach Nunzio Campanile, who was tight ends coach at this time last week before head coach Chris Ash was shown the door.

Expatriate of the Week

Oklahoma State’s Matt Ammendola, a graduate of North Penn High School, is the only FBS kicker who is perfect on field-goal and extra-point attempts while making at least 10 field goals. The senior leads the nation in total points among kickers with 54, and is fifth in average points at 10.8 per game. He is 10-for-10 on field goals and 24-for-24 on extra points.