This Page presents the user with the chance to determine if a certain number is prime. The calculation is accurate up through a number 16 digits long.

This page can help with determining the Least Common Denominator of Numbers. It is also a good idea to review the divisibility test criteria listed at the bottom of the page.

Please enter a number and then press the Determine button:

Divisibility Tests:

A Natural Number is Divisible by

2

If the Number is Even

3

If the Sum of the Digits is divisible by 3

4

If the last 2 digits is a number divisible by 4

5

If the last digit is 5 or 0

6

If the Number is even and divisible by 3

8

If the number is divisible by 4 and the result is even

9

If the sum of its digits is divisible by 9

10

If the last digit is 0

Email Jim Dildine Date Last Modified: 8/31/99 James P. Dildine