Practice Prime Numbers in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

Integers greater than 1 whose only positive divisors are 1 and themselves—they cannot be factored further.

Primes can't be broken down further—they're the 'atoms' of multiplication.

Showing a random 20 of 50 problems.

Example 1

hard
Determine whether gcd(210,310)=1\gcd(2^{10}, 3^{10}) = 1 and explain.

Example 2

medium
Write the prime factorization of 6060.

Example 3

hard
Determine whether 221221 is prime.

Example 4

easy
List all prime numbers between 20 and 40.

Example 5

medium
What is the smallest prime greater than 5050?

Example 6

hard
What is the smallest positive integer with exactly 44 distinct prime factors?

Example 7

medium
Find the prime factorization of 360360.

Example 8

medium
Find the prime factorization of 8484.

Example 9

medium
What is the largest prime factor of 9090?

Example 10

hard
If pp and p+2p + 2 are both prime and p>3p > 3, prove that p+1p + 1 is divisible by 66.

Example 11

hard
How many divisors does 720720 have?

Example 12

easy
List all primes between 4040 and 6060.

Example 13

easy
Find the prime factorization of 180180.

Example 14

hard
Find a prime pp such that pp, p+4p + 4, and p+8p + 8 are all prime.

Example 15

easy
Is 1313 a prime number?

Example 16

easy
What is the only even prime number?

Example 17

challenge
Find the smallest number with exactly three distinct prime factors.

Example 18

medium
Is 143143 prime?

Example 19

hard
What is the sum of all primes less than 2020?

Example 20

challenge
Prove there is no largest prime (Euclid's idea, briefly).