Logic Masters Deutschland e.V.

Standard sudoku rules apply.
Standard variant rules apply:

• Digits in grey circles are odd.
• Digits in killer cages sum to the total in the upper left.

Prime Boxes:
In boxes 2, 3, 4, 6, 7, and 8 (where box 1 is the 9 cells in the upper left corner of the grid), each digit contributes to at least one two-digit prime number contained within that box, where numbers are read left-to-right or downwards.

Hint:
If you are having difficulty with the prime box rule, this visual guide may help: https://imgur.com/a/7ImYK7V . (Try figuring it out yourself first!)

Solve on the CtC app here.
Solve on F-puzzles here.