How this works
Enter the values shown, review the result, and verify assumptions before acting. The calculation is performed on your device without uploading these entries.
Determine whether a nonnegative integer is prime by checking possible divisors. The input fields are labeled with the units or formats used in the calculation. Change one value at a time to see how the result responds, and compare the output with the worked example below.
Formula or method
The method above describes the calculation or algorithm being used by this browser utility. It is shown so you can understand the result, check assumptions and repeat the calculation independently if needed.
Worked example
97 is prime; 91 is divisible by 7.
Limitations and accuracy
Large integers can be slower; uses browser safe integer limits.
The calculation runs locally in your browser. No result is guaranteed to be suitable for financial, legal, medical, or safety-critical decisions. Check independent authoritative sources in those cases.
More context
A fair random draw gives each eligible item an equal chance under the stated sampling method. Drawing without replacement means selected items cannot appear again, whereas independent draws permit repeats. Cryptographically generated browser random values avoid some biases of simplistic pseudo-random formulas. A casual randomizer is not a regulated lottery service and should not be presented as independently certified.