Poincaré died one hundred years ago, in July 1912. He was a French mathematician who also wrote essays on the nature of mathematics. I happened to visit his Wikipedia page today, which would be his 158th birthday anniversary. In the days before Wikipedia, this was a leading source for Poincaré's biography online in English. Also try this.
I wonder how many mathematicians there are in the world.
If "a mathematician is a person with an extensive knowledge of mathematics, a field that has been informally defined as being concerned with numbers, data, collection, quantity, structure, space, and change" (source) then I suspect that the number of people that I would consider to be mathematicians is 100,000 - 200,000.
You could think about membership of the American Mathematical Society (about 30,000)
Multiply by 3 (for counterparts in Europe/former SovietUnion and Other) = 90,000.
Double that number to reflect those outside pure mathematics but close enough = 180,000.
I also like this estimate of 150,000 people.
Other fun data: SIAM, Society for Industrial and Applied Mathematics has ~13,000 members, while Association of Women in Mathematics has ~2000 members.
NUMB3RS again. Charlie is a fictional math genius who teaches at CalSci but often assists his crime-busting brother at the FBI. This TV show features imaginative and engaging stories of math life. I find it inspiring.