| Answer | Crossword Clue |
|---|---|
| NINETEENS | Prime numbers. |
| ODD | Like most prime numbers |
| ONE | Number of even prime numbers |
| ODD | Like all prime numbers but 2 |
| ODD | Like all prime numbers besides one |
| ODD | Like all prime numbers except 2 |
| ODD | Like all prime numbers but one |
| SIEVE | ... of Eratosthenes (method for finding prime numbers) |
| NULLSET | Intersection of perfect squares and prime numbers |
| TEN | Sum of the first three prime numbers |
| CICADA | Bug that hibernates for prime numbers of years, helping it avoid predators |
