Manipulating hexadecimal values in java

I'm tying to make a Linear Congruential random number generator, and I want to select, say the first 16 bits of a 64-bit length hexadecimal value. How Can I do this in java? I've already created a (very) basic generated number based on the time of day.

My formula:

seed = 0x5D588B656C078965L * cal.get(Calendar.HOUR_OF_DAY) + 0x0000000000269EC3;

I just want to select the first 16 bits of this, I tried to think of how I would do this with an integer but the I don't think i can apply the same concepts here. Thanks!