Logic Masters Deutschland e.V.

Same rules as in crossword puzzles, but instead of words the solutions are numbers.

All tasks have a unique solution, if you want it a little more difficult, you can solve the puzzle without using the grid.

1. The smallest prime number greater than 10 with consecutive digits.
2. The largest number, whose digits are all different.
3. The largest palindrome, whose digits are prime with each digit allowed to appear twice.
4. The smallest 8-digit number, whose digit sum is prime.
5. The smallest number with digit product 525.
6. The smallest 8-digit number divisible by 2, 3 and 4.
7. The largest number with digit sum 12, whose adjacent digits have a difference of at least 5.
8. The smallest 7-digit number, where every digit d appears exactly d times in the number. (e.g. if the number contains the digit 5, the digit 5 appears 5 times in the number.)
9. When will be the next day, where the date is a palindrome? (An 8 digit number: DDMMYYYY)
10. The smallest non-prime number not divisible by 2, 3, 4, 5, 6, 7, 8, 9 and 10.
11. The number of days since January 1, year 1, where every digit of the date is ascending and consecutive. (Day and month do not contain leading zeros. 21 June 2025 is written as 21.6.2025)
12. A number less than 77 with exactly 7 divisors.

Solution code: The green digits, top to bottom, left to right.

Solution code without using the grid:
1st digit of solution 1
5th digit of solution 2
4th digit of solution 5
2nd digit of solution 7
5th digit of solution 4
7th digit of solution 9
7th digit of solution 3
3rd digit of solution 8
1st digit of solution 10
Last digit of solution 11
1st digit of solution 12
Last digit of solution 6