It is believed that on Cheops alone 100,000 men were employed for twenty years. And when it was finished all that Egypt had to show for 600,000,000 days of human labor was a frozen asset.
A Bubble That Broke the World by Garet Garrett (pg. 31)

It is believed that on Cheops alone 100,000 men were employed for twenty years. And when it was finished all that Egypt had to show for 600,000,000 days of human labor was a frozen asset.