Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thirty-Six Unsolved Problems in Number Theory   Partially or totally unsolved questions in number theory and geometry
especially, such as coloration problems, elementary geometric conjectures,
partitions, generalized periods of a number, length of a generalized period,
arithmetic and geometric progressions are exposed.

6
The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph