Alaska and Hawaii are the only two states that do not share a border with another state.
The question does not make sense. All of the states of Australia share a border with another state. Even Tasmania, the island state, shares an actual land border as well as a water border with another state.
All states but Alaska and Hawaii border at least one other state. Maine is the only state to border just one state.
Maine
Kentucky
No...Maine shares a common border with only one state - New Hampshire
There are 32 U.S. states each of which shares a border with at least one other U.S. state AND does not share a border with any Mexican state or Canadian province. Of those 32, there are 18 U.S. states that do not border international waters either (i.e., do not border the Pacific Ocean, the Atlantic Ocean, or the Gulf of México).
No state borders California to the west. Hawaii is the only state west(ish) of California but they do not share a border.
Juneau
Only Alaska and Hawaii do not share borders with other US states. Every other state shares a border with at least one other state.
Only Alaska which has a maritime border with Russia.
Oman and Iran share only a sea border in the middle of the Gulf.