Mercury has an equatorial circumference of 15,329 kilometers. That's only a little bigger than Earth's moon.
Mercury has a volume of 60,827,208,742 cubic kilometers. That might seem like a big number, but it's smaller than all of the other planets.
If we put Mercury on a balance, it would have a mass of 330,104,000,000,000,000,000,000 kilograms.
Being a terrestrial planet, Mercury has a relatively high density of 5.42 grams / cubic centimeters. It would definitely sink in water.
Because of it's low mass, Mercury has a gravitational pull of only 3.7 meters / seconds squared. This is less than half of Earth's gravitational pull.
It takes Mercury 1,407.5 hours to complete one rotation. That's almost two months!
Because it is closest to the Sun, Mercury orbit is relatively short and it's able to complete a revolution in 0.24 earth years.
Mercury has an axial tilt of 0 degrees. That means it has no tilt at all and experiences no seasonal changes.
Mercury's temperatures change wildly between day and night. It's average temperature is 66.9 degrees Celsius. That's too hot for humans to survive.