I see you are looking for a specific number, but it is more complicated than that.
Kelvin (K), refers merely to the temperature of the light (anywhere from a warm (in the say 2,000K area, which will appear rather yellowish/orange), to very cool daylight (around 6,000K and a bit blue toned and crisp).
With just that knowledge you would need more lumens of a 2,700K light to get the clarity you would see with a 6,000K light source.
So, this is what you are after:
The Kelvin of the light should be closer to the 6,000K level as you will receive better clarity working on white paper with a black or dark ink.
The light should not be so bright that it causes glare from the paper surface. If the paper is reflecting too much light back at you, your eyes will strain and your drawing will not be 100% accurate as intended for your skill level.
In the best case however, you would have overhead “general room lighting” bright enough to see clearly the objects in the room without strain. Plus, you really should have an adjustable Task Light with a high Kelvin rated bulb, so you can adjust it as needed for the drawing.
Truly hoping this helped and that you can add a task light to your arrangement!