# Prize crossnumber, Issue 17

Can you solve it?

Our original prize crossnumber is featured on pages 58 and 59 of Issue 17.

### Rules

• Solvers may wish to use the OEIS, Wikipedia, Python, a slide rule, etc to (for example) obtain a list of cube numbers, but no programming should be necessary to solve the puzzle. As usual, no numbers begin with 0.
• One randomly selected correct answer will win a £100 Maths Gear goody bag, including non-transitive dice, a Festival of the Spoken Nerd DVD, and much, much more. Three randomly selected runners up will win a Chalkdust T-shirt. Maths Gear is a website that sells nerdy things worldwide, with free UK shipping.
• To enter, submit the sum of all the digits in the row marked by arrows using this form by 23 September 2023. Only one entry per person will be accepted. Winners will be notified by email and announced on our blog by 1 November 2023.

### Crossnumber

Crossnumber #17, set by Humbug:

### Across clues

• 1. An anagram of 3D that is a palindrome. (5)
• 4. An anagram of 7A. (4)
• 6. A multiple of 51A. (3)
• 7. 7 times 4A. (4)
• 9. The number of the down clue whose answer is equal to the number of white squares in this crossnumber grid. (2)
• 10. Every digit of this number is even. (3)
• 12. 5 more than a palindrome. (7)
• 16. 7 times 6A. (3)
• 17. The number of the across clue whose answer is 17. (2)
• 18. The first four digits of 19D. (4)
• 20. One more than the product of 38A and 38D. (5)
• 21. The number of the across clue whose answer is 21. (2)
• 22. Every digit of this number is the same. (6)
• 27. The sum of this number’s digits is 5. (6)
• 30. An anagram of 86420. (5)
• 31. An anagram of 19D. (7)
• 32. The number of the down clue whose answer is 131. (2)
• 33. The sum of this number’s digits is 5. (6)
• 35. The sum of the digits of 35D. (2)
• 36. A multiple of 46A. (4)
• 38. An even number. (3)
• 40. A multiple of 51A. (5)
• 43. A multiple of 11111. (5)
• 45. 5 more than a palindrome. (3)
• 46. A multiple of 3. (3)
• 47. An anagram of 9630. (4)
• 48. An odd number. (2)
• 49. The number of the down clue whose answer is 653. (2)
• 51. Greater than 9A. (2)
• 52. 5 more than a palindrome. (4)

### Down clues

• 2. A palindrome. (4)
• 3. An anagram of 1A that is 5 more than a palindrome. (5)
• 4. The sum of the digits of 24D. (2)
• 5. A square number. (3)
• 6. The last 6 digits of 12A. (6)
• 8. The number of distinct pentominoes* that can be made. (2)
• 9. An odd number. (3)
• 11. 5 more than a palindrome. (11)
• 13. A multiple of 3. (5)
• 14. The number of the down clue whose answer is 11. (2)
• 15. The number of the down clue whose answer is 15. (2)
• 19. Each digit of this number (except the first) is less than or equal to the previous digit. (7)
• 22. The product of 39D and 17A. (5)
• 23. One more than 34D. (2)
• 24. An odd number. (4)
• 25. The final digit of this number is the first digit of 5D. (3)
• 26. 15D squared. (3)
• 27. 20 less than 29D. (3)
• 28. 10 more than 27D. (3)
• 29. 10 more than 28D. (3)
• 34. One less than 23D. (2)
• 35. An odd number. (3)
• 37. A multiple of 9. (5)
• 38. An odd number. (2)
• 39. An odd number. (3)
• 40. The sum of this number and 50D is 26D. (3)
• 41. The number of the down clue that is equal to 48A squared. (2)
• 42. The sum of this number’s digits is 11. (4)
• 44. A multiple of 1111. (4)
• 46. The number of the across clue whose answer is 1089. (2)
• 50. 5 times 8D. (2)

* A pentomino is a polygon made by joining five squares edge-to-edge. Pentominoes that are rotations of each other are considered the same, but those that are reflections of each other are considered distinct.

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