The US president’s compensation is far more than $400k per year including all the post employment benefits. Just the $200k+ per year annuity (inflation adjusted to boot) for the rest of their life is worth millions if they live more than ~6 years, and it only takes 4 years to earn it. Due to his young age, Obama easily got a few extra millions per year just in the value of the annuity.

https://www.thoughtco.com/presidential-retirement-benefits-3...