The Earth's equatorial circumference is 24,901.55 miles. However, when taking measurements passing through the poles, that number decreases to 24,859.82 miles around.
The Earth's shape allows for slight variations in its circumference. Instead of having a perfect sphere shape, the Earth is an oblate spheroid. Due to its shape and the variations in its circumference, it is faster to fly around the Earth passing through its poles rather than flying around its circumference. The Earth's size is dwarfed by other planets in the solar system, including Jupiter, with an equatorial circumference of 279,118 miles, and the sun, which has an equatorial circumference of 2,720,000 miles.