I am not sure why it shows up like that, but there is no more hashing at all on the network so the number is invalid anyway.

The "difficulty" is apparently 4294967295 but I'm not sure why.  I will have to ask Roman.  If it is 4294967295 though and the network gets one block every 15 seconds (default delegate staking time) then if it were hashing, it would need 68.27 MH/sec.