I need to have one cell in a sheet generate a random number without changing
after calculations are entered in other cells.

What I've tried so far:
=randbetween(111111,999999)

But this number keeps changing every time any other data is entered into
other cells in the sheet, or a calculation processes.

So, I disabled calculations, but that won't work b/c I need to have the
calculations available.

Oh, and I can't use macros b/c the sheet is going to be posted on the net.

Any suggestions for generating one random number and keeping it? Thanks