Controlling W2812B LED strip

I have a bit of code for controlling LED strips. Not familiar with what the L is in this part of code
int hue = firstPixelHue + c * 65536L / strip.numPixels(); What is the 65536L?

Designates it as a long number if I remember correctly

That number is too large to be treated as an integer or as an unsigned int and then the type “long” is needed.

Or unsigned long, for 0 to (2^32)-1