How to Use Prime95: Program Output

# PROGRAM OUTPUT

## On screen you will see:
Factoring M400037 to 2^54 is 3.02% complete. Clocks: 24235224=0.121 sec.

This means prime95 is trying to find a small factor of 2^400037-1. It is 3.02% of the way though looking at factors below 2^54. When this completes it may start looking for factors less than 2^55.

## Iteration: 941400 / 1667747 [56.45%]. Per iteration time: 0.109 sec.

This means prime95 just finished the 941400th iteration of a Lucas-Lehmer primality test. The program must execute 1667747 iterations to complete the primality test. The average iteration took 0.109 seconds.
The results file and screen will include lines that look like:

## M2645701 has a factor: 13412891051374103

This means to 2^2645701-1 is not prime. It is divisible by 13412891051374103.

## M2123027 no factor to 2^57, WV1: 14780E25

This means 2^2123027-1 has no factors less than 2^57. The Mersenne number may or may not be prime. A Lucas-Lehmer test is needed to determine the primality of the Mersenne number. WV1 is the program version number. 14780E25 is a checksum to guard against email transmission errors.

## M1992031 is not prime. Res64: 6549369F4962ADE0. WV1: B253EF24,1414032,00000000

This means 2^1992031-1 is not prime - a Lucas-Lehmer test says so. The last 64 bits of the last number in the Lucas-Lehmer sequence is 6549369F4962ADE0. At some future date, another person will verify this 64-bit result by rerunning the Lucas-Lehmer test. WV1 is the program version number. B253EF24 is a checksum to guard against email transmission errors. 1414032 can be ignored it is used as part of the double-checking process. The final 00000000 value is a set of 4 counters. These count the number of errors that occurred during the Lucas-Lehmer test.

## M11213 is prime! WV1: 579A579A

This means 2^11213-1 is a Mersenne prime! WV1 is the program version number. 579A579A is a checksum to guard against email transmission errors.