3727

This number is a prime.

The largest prime that is the sum of no fewer than 17 biquadrates (4th powers). [Post]

(2*2^9)+(3*2^8)+(5*2^7)+(7*2^6)+(11*2^5)+(13*2^4)+(17*2^3)+(19*2^2)+(23*2^1)+(29*2^0) = 3727. [Bergot]