Is 29 a prime number?

• A. I don't know
• B. Sometimes
• C. No
• D. Yes

Answer: (D)

A prime number is a natural number greater than 1 that has exactly two positive divisors: 1 and itself. To tell if 29 is prime, look for any divisor besides 1 and 29. You only need to check up to the square root of 29, which is a little over 5, so check 2, 3, and 5.

• Not divisible by 2 (29 is odd).

• Not divisible by 3 (29 ÷ 3 is not an integer).

• Not divisible by 5 (29 ÷ 5 is not an integer).

Since no numbers up to 5 divide 29 evenly, there are no divisors other than 1 and 29. That means 29 has exactly two positive divisors, so it is prime.