According to the work produced by David B. Barrett's religious statistics organisation (FYI, the man was a Christian no less) atheists number more than Jews, Sikh's, Shintos, Baha'is, Jains, combined, and if you want to consider all «
non - religious /
secular / agnostic / atheist» together, since the whole «
non-religion» movement is kinda riddled with
people who find conontations of words like «atheist» to be bad enough to not want to declare themselves atheist, you'll find the number of that
non-religious group also amounts more than those religions plus buddhism, and taoism or even Confucianism.