According to a 2011 Pew Research Center survey, there were 2.2 billion Christians around the world in 2010, up from about <answer>600 million</answer> in 1910. By 2050, the Christian population is expected to exceed 3 billion. According to a 2012 Pew Research Center survey Christianity will remain the world's largest religion in 2050, if current trends continue.
How many Christians were in the world in 1910?
600 million