This can operate in three ways:

1: You can enter a number in the lowe most input field, and check if it is
a prime number or not.

The test done is the Miller-Rabin primality test looped 33 times.

The risk for a false positive is in the order of 1/4 ^{33} or one
in about 7·10^{19}.

For small numbers (<9·10^{15}) it will also do an exact
test. This may

take a few seconds.

2: This will first generate a random integer with the required number

of decimal digits. It will then be turned to the form 6n-1. Then that
number,

the number +2, then +4, then +2 and so will be tested until prime number
is reached.

If the search takes too long, click enter again.

Required number of digits:

3: This does the same, but it generates a random integer with the required number of bits.

Number of bits:

The prime number