Those big numbers are pretty rare.
For instance, the list
https://docs.google.com/spreadsheet...am9mTkpVVmhiRzJpTl9jLVlIaVE&usp=sharing#gid=0 contains 240 EU numbers and none of them is above 53xxx. Distribution of numbers up to 53xxx seems pretty uniform if we exclude Ukraine and Uzbekistan from the list. So, the fact that we do not have numbers between 54xxx and 59xxx in that list means there is really a tiny percentage of those numbers, if any.
This particular number seems a little bit strange, because the person reveals all digits but one (59x22). We had an example here on the forum where a number with almost all digits known was not real. Anyway, with 95% confidence we could say that probability to have a number higher than 53xxx is less than 1.25% (because 240 numbers we have in the list are all under 54000).