Number who have ever been born 106,456,367,669
I found the exact same figure, and did some calculating...
There are roughly 57,500,000 square miles of dry land on planet earth.
This equates to approximately 1,603,008,000,000,000 square feet (27,878,400 square feet in a square mile)
This allows 15,057 square feet for every person who has ever lived (106,456,367,669 into 1,603,008,000,000,000 = 15,057 square feet)
15,057 square feet = .00054 square miles (27,878,400 square feet in a square mile)
15,057 square feet = 1,399 square meters (10.76 square feet in a square meter)
15,057 square feet = 1,673 square yards (9 square feet in 1 square yard)
To put it into perspective, that's roughly a 1/3 of an American football field (1673 divided by 5000 = .3346)
Here's the kicker. The 57,500,000 square miles of land on earth includes all dry land, including forests, jungles, deserts, high mountains, tundra, etc. Only about 1/4 of all dry land (approximately 14,373,000 square miles) is arable, meaning it can be cultivated and used to grow food
Do the math