Richard Williamson proved that all odd numbers are polite:
This is because any odd number can be expressed as an even number
+ 1 and hence is the sum of half that even number, and the next
integer. For instance, 13 = 6 + 7, 45 = 22 + 23, etc, where 6 and
22 are half of 12 and 44 respectively. As an odd number can
always be expressed as the sum of two consecutive integers, and
as this satisfies the definition of politeness, all odd numbers
are polite.
Richard also found the consecutive sums for 544 and 434 and the
way of characterizing impolite numbers, namely that they are all
powers of 2. All other integers are polite. Shu Cao of the Oxford
High School for Girls also proved this result.
James Newton of Hills Road Sixth Form College, Cambridge proved
this result and also gave a nice generalization defining a
'degree of politeness' of numbers.