9
3
7
1
Answer is Right!
Answer is Wrong!
The missing number is 1.
The numbers in the sequence are all prime numbers, except for the missing number. The missing number must be a prime number that is not in the sequence. The only prime number that is not in the sequence is 1.
A prime number is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number.