The closest distance will be 3,334,000 miles. That's 14 times the distance from Earth to the moon.
Potentially hazardous means that its orbit brings it close enough to earth that it could at some time in the future be deflected by earth’s gravity (or other perturbing forces) into a collision course with earth, not that a collision is presently predicted or predictable.
It’s orbit carries well inside of Mercury’s to far (over 100,000,000 miles) past the orbit of Mars. It is moving smartly when it crosses the distance of earth’s orbit (it has enough kinetic energy to go another 150,000,000 further miles from the sun before it begins to fall back again towards it.) It is moving about 25 km/sec with respect to earth when it crosses earth’s orbit. If it ever hits earth, it will do a LOT of damage.