A prime number is a number that is bigger than one and cannot be divided evenly by any other number except one and itself. This article will help you find out if a number is prime or not using the following methods: factor trees, a calculator or divisibility. However, sometimes when dealing with large numbers, you may want to use the prime number calculator.
When numbers are quite large, you may find this website showing an expanding prime number archive currently sitting on 20 billion numbers discovered and indexed. You can use multiple search methods to find a page
based on index or the prime number in question. A great, free service to any math enthusiast or computer science individual.