Prime numbers

A prime number can be divided, without a remainder, only by itself and by one. All prime numbers must be, by definition, greater than one.

Prime number test for small numbers

Enter the number to test:


result:


How the small prime number test works:

This test iterates through all number form two to the square root of the number-to-test to see if it is a divisor of the number-to-test. It is a reliable method but it can not be used for very large numbers since the calculation would take a very long time. There is as well a limit to the number size that web browsers can handle natively independent of the underlying CPU architecture.

To use this test you enter the number which you want to test (e.g 2003) and then you press "test number" to see if it is prime or not.


List of prime numbers between 1 and 1000

2     3     5     7     11    13    17    19    23 
29    31    37    41    43    47    53    59    61 
67    71    73    79    83    89    97    101   103
107   109   113   127   131   137   139   149   151
157   163   167   173   179   181   191   193   197
199   211   223   227   229   233   239   241   251
257   263   269   271   277   281   283   293   307
311   313   317   331   337   347   349   353   359
367   373   379   383   389   397   401   409   419
421   431   433   439   443   449   457   461   463
467   479   487   491   499   503   509   521   523
541   547   557   563   569   571   577   587   593
599   601   607   613   617   619   631   641   643
647   653   659   661   673   677   683   691   701
709   719   727   733   739   743   751   757   761
769   773   787   797   809   811   821   823   827
829   839   853   857   859   863   877   881   883
887   907   911   919   929   937   941   947   953
967   971   977   983   991   997                  


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© Guido Socher, version 2017-11-06