If you have any interest in estimating your number among the 7 billion, BBC News World has provided a calculator.
That calculator indicates:
When I was born, I was the the 2,706,590,438th person alive and the 76,044,892,501st person to have lived. My Mother-in-Law’s # is 1,949,405,196th ….
Learn more at 7billionandme.org.