OverflowError sometimes (but not always) includes some sort of numeric code:

>>> 1e+300 ** 2
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OverflowError: (34, 'Numerical result out of range')

but the meaning of the 34 is not documented:

https://docs.python.org/3/library/exceptions.html#OverflowError

help(OverflowError) is no more insightful, saying only:

    __init__(self, /, *args, **kwargs)
        Initialize self.  See help(type(self)) for accurate signature.

Other OverflowError exceptions do not include the numeric code:

>>> math.exp(10000)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OverflowError: math range error

Is it an error code from C? Something to do with the number of digits of precision? An easter-egg to do with The Count Of Monte Cristo?