No, nitrous oxide N2O is not flammable. Nitrous oxide is a weak oxidizer and can be used to provide extra oxygen when can assist in burning other materials. However, nitrous oxide only releases its oxygen from its bod with the nitrogen (and thus be able to assist with burning other materials) at high temperatures (~300C).
Full (unopened) nitrous oxide canisters should not be burnt however as they may explode.
Nitrous Oxide cream chargers are a popular product that is used to whip cream. You can purchase cream chargers on Best Nangs.