In my country (Germany) afaik a little over 10% of the population are at least millionaires. So I think the likelihood to have a millionaire living next door is quite high.
And if we are talking average income, then everyone on this side of the village is a millionaire simply because of those two. However, most of the rest of us seem to struggle daily.
Sometimes real estate the owners live in themselves is not counted?
With 1.6% the odds of having a millionaire neighbor would still be high.