Beal conjecture
The Beal Conjecture is the USD $1,000,000 prize conjecture created by Andrew Beal in 1993, which has come to be worth 7 figures over nearly 30 years; a 2-year wait is lifted by the Beal bank on winnings, according to the conjecture's website. It is a generalization conjecture of FLT, the last conjecture of Pierre de Fermat. So in terms of valuation of the prize, it's worth less than a million; due to the time value of money or TVM.