Find the missing number?

4
1
7
2

The answer is 7.

The numbers in the sequence are the first 10 prime numbers, starting with 2. The missing number is the 7th prime number, which is 7.

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.

The first 10 prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23, and 29.