Zero.
The prime meridian is a line of longitude. Nothing can be closer to something than itself.
Lime, Peru is 77.1 degrees of longitude from the Prime Meridian, and about 5,005 miles from the closest point on it. Philadelphia, PA is 75.2 degrees of longitude from the Prime Meridian, and about 3,304 miles from the closest point on it. Philadelphia wins both measurements.
Zero degrees ! The Prime Meridian is the starting point for the angular divisions around the globe.
The Prime Meridian itself is defined as zero longitude. (0°) You can't get any closer to it than that. The higher the number of degrees of longitude, the farther a given longitude is from the prime meridian. The maximum is 180° either east or west. There is no minimum. Whatever longitude you name, no matter how close it is to the Prime Meridian, I can always name one that's closer to it than yours is. It's like asking "What is the smallest number ?" There's no such thing.
The Prime Meridian is a line of longitude, and it sits at 0 degrees longitude.
the prime meridian is the starting point when measuring the longitude
Prime Meridian. 180 longitude is the Iinternational Date Line, and the equator is 0 degrees latitude
The Prime Meridian is the definition of zero longitude.
The Prime Meridian is located at 0 degrees longitude. It serves as the starting point for measuring longitude and divides the Earth into the Eastern and Western Hemispheres.
The prime meridian is at 0 degrees longitude. Therefore, any longitude close to the prime meridian would be a value close to 0 degrees, such as 1 degree or -1 degree longitude.
The longitude of every point on the Prime Meridian is Zero.
The Prime Meridian is at zero degrees longitude and every possible latitude.