There is a binary test called PRIME? on the WP34S (yes, the old one). It works fine there since "the method is believed to work for integers up to 9E18" as stated in its manual. I checked with DBLON and found primes at 9'000'000'000'000'000'053, ...157, ...191, ...317, etc. up to 9'223'372'036'854'775'783. The latter is the maximum prime found by the WP34S.

For the WP43S we've implemented a procedure working up to 3'317'044'064'679'887'385'961'981. This means almost 6 orders of magnitude more than the WP34S covers. Does anybody need even greater primes? If yes, how great and what for?

## Prime number needs

### Prime number needs

DM42 SN: 00041 β

HP-35, HP-45, ..., HP-35S, WP 34S, WP 31S, DM16L

**WP 43S running**on this deviceHP-35, HP-45, ..., HP-35S, WP 34S, WP 31S, DM16L

### Re: Prime number needs

LOL. No one

*needs*any primes at all. I think the question you intend to ask is: "Does anybody whimsically desire even greater primes?" To which the answer will almost certainly be yes. I look forward to reading the uses and justification.

Keep it up team 43S!

--bob p

DM42: β00071 & 00282, DM41X: β00071 & 00656, DM10L: 071/100

DM42: β00071 & 00282, DM41X: β00071 & 00656, DM10L: 071/100

### Re: Prime number needs

They hide in the bushes and don't dare showing up

DM42 SN: 00041 β

HP-35, HP-45, ..., HP-35S, WP 34S, WP 31S, DM16L

**WP 43S running**on this deviceHP-35, HP-45, ..., HP-35S, WP 34S, WP 31S, DM16L

### Re: Prime number needs

I want to set a new Guinness World Record. You asked...

DM42 #40 running C43 | DM41X #50 | various HP models

The earth

The earth

*is*flat. It just appears round because it is massive and curves spacetime.### Re: Prime number needs

Declined for lack of use and justificationH2X wrote: ↑Tue Mar 17, 2020 5:26 pmI want to set a new Guinness World Record. You asked...

DM42 SN: 00041 β

HP-35, HP-45, ..., HP-35S, WP 34S, WP 31S, DM16L

**WP 43S running**on this deviceHP-35, HP-45, ..., HP-35S, WP 34S, WP 31S, DM16L

### Re: Prime number needs

I use

The 34S limits it prime testing to 2⁶³ from memory due to a problem in my implementation of the test.

Pauli

**far**larger primes in my day job.The 34S limits it prime testing to 2⁶³ from memory due to a problem in my implementation of the test.

Pauli

### Re: Prime number needs

1. How far is

**far**?? (Good grief, we're talking about numbers here, aren't we? )

2. The actual limit of the 34S is found above - no need for stressing memory.

DM42 SN: 00041 β

HP-35, HP-45, ..., HP-35S, WP 34S, WP 31S, DM16L

**WP 43S running**on this deviceHP-35, HP-45, ..., HP-35S, WP 34S, WP 31S, DM16L

### Re: Prime number needs

Interesting! To the extent that you can, plz tell us what they are used for. Presumably some form of encryption, but it would be really interesting to find out if they are useful in other applications.

--bob p

DM42: β00071 & 00282, DM41X: β00071 & 00656, DM10L: 071/100

DM42: β00071 & 00282, DM41X: β00071 & 00656, DM10L: 071/100

### Re: Prime number needs

Beyond cryptographic applications, we're looking forward to whoever can name another use of great primes ("great" as specified above).

DM42 SN: 00041 β

HP-35, HP-45, ..., HP-35S, WP 34S, WP 31S, DM16L

**WP 43S running**on this deviceHP-35, HP-45, ..., HP-35S, WP 34S, WP 31S, DM16L

- Mark Hardman
**Posts:**116**Joined:**Wed May 03, 2017 3:26 am**Location:**Houston, TX

### Re: Prime number needs

From the Wikipedia article on the Mersenne Twister pseudo-random number generator:

It also appears that large primes are used for the Lehmer random number generator:

Though these four primes fall far short of the "great" categorization.

*The most commonly used version of the Mersenne Twister algorithm is based on the Mersenne prime 2^(19937)−1.*It also appears that large primes are used for the Lehmer random number generator:

*Mersenne primes 2^31−1 and 2^61−1 are popular, as are 2^32−5 and 2^64−59*Though these four primes fall far short of the "great" categorization.

DM42: β00043, β00065, 00357 / DM41X: β00054, 00445

DM10L: 017/100, DM11L: 00121, DM12L: 02005, DM15L: 00523, DM16L: 00008, DM41L: 00111

DM10L: 017/100, DM11L: 00121, DM12L: 02005, DM15L: 00523, DM16L: 00008, DM41L: 00111