Interesting Question about Human Procreation

It is said that the whole population of the world can fit shoulder to shoulder on the Isle of Wight in the UK. The IOW is 147 Sq Miles.

How long would it be therefore, considering exponential procreation, before all land mass on earth would be filled by humans shoulder to shoulder ? The land mass on earth is 57,308,738 square miles.

Although taking away deserts and mountainous regions leaves 24,642,757 square miles.

Have a think - you must take into account how fast 2 people produces another and so on and so on...????