Mariah Carey, Nick Cannon … The Cost of Emancipation from Mimi

EXCLUSIVE

Mariah Carey and Nick Gun have a prenup with a confidentiality clause … and if she blabs out of school she gets socked for twice what he’d have to pay if he violates it.

Sources familiar with the situation tell TMZ … if Nick violates the confidentiality clause he has to pay her a $ 250,000 penalty, but if she spills the beans she has to pay him $ 500K.

And the prenup makes it clear … Mariah came into the marriage with a boatload of money … Nick, not so much.

The prenup says Mariah is worth $ 150 million … she has so much, $ 30 million is listed as “miscellaneous.” Nick came into the marriage in 2008 with a little less than $ 500K.

He’s done well since then, making millions on his various projects, but when they married he finished up buying her engagement ring for $ 500,000 but took a loan out for $ 470K. The ring was reportedly worth $ 2.5 mil, but that’s not what he paid.

As we reported … they’ve already worked out a full material goods agreement covenant.