Literature value ~ 60 m / 106 yrs.
Mean Elevation of continents: 840 m.
Time to completely erode land:
840 m / (60 m per 106 yrs) = 14 million years.
Implications:
Erosion would rapidly reduce continents to sea level if there were not an opposing process (mountain building and volcanic eruptions).
Erosion is highly concentrated in areas of high elevation and rapid mountain building.