It is hard for me to do two things at the same time. I can't talk while making love and when I read I don't want any sound around, no music, nothing. So if you have to study, I could not advise you, even if I was your daddy, to study with music. But just for the sake of the topic, Bach wrote so much music, I only am familiar with a fragment of the work, the Brandenburger Concerts, I like to put them on on Sunday mornings, not too loud, are for me very enjoyable; there is a little zing of 'musak' in it, suitable as background music. For the rest, Bach is too profound, serious, overwhelming, too good in comparison to everything else. Another option is studying math in as much silence as possible and then having an afternoon nap with a record of the Well Tempered, eyes shut, and let the math material, while slightly being in a sleepy-dreamy state, sink down and settle in your brains. Eventually wake up and start the whole process over again.
Anyways, good luck.
Topic: Listening to piano works by Bach while studying maths