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Number primality tester

World's simplest number tool

Quickly test if one or more numbers are prime numbers in your browser. To perform the check, just enter your numbers in the input field, select the primality test method in the options below, and this utility will display the status of your numbers. Created by developers for developers.
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Primality Test Method
Print the number followed by whether it's a prime or not.
Print only numbers that are prime.
Show only numbers that are сomposite.
Number primality tester tool What is a number primality tester?
This is an online browser-based utility for running the primality check algorithm on one or more numbers. The tool tests if the given number has a divisor that is different from 1 and the number itself. If such a divisor exists, then your number is a composite, otherwise, your number is prime. The tool can check multiple numbers at once if they are listed as rows in the input. At the same time, you can define the test method – show a full analysis of all numbers, display only a list of primes, or get only composites. That's numberwang!
Number primality tester examples Click to use
Primality Test for First Ten Odd Numbers
This example checks the first 10 odd numbers for primality, showing a full analysis for each number. As a result, you can see that there are 7 prime numbers and only 3 сomposites.
1 3 5 7 9 11 13 15 17 19
1 is not a prime 3 is a prime 5 is a prime 7 is a prime 9 is not a prime 11 is a prime 13 is a prime 15 is not a prime 17 is a prime 19 is a prime
Required options
These options will be used automatically if you select this example.
Print the number followed by whether it's a prime or not.
Filter Prime Numbers
In this example, we run the primality test algorithm for all numbers from 500 to 600. To simplify the results, we show only primes and ignore composite numbers.
500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600
503 509 521 523 541 547 557 563 569 571 577 587 593 599
Required options
These options will be used automatically if you select this example.
Print only numbers that are prime.
Filter Composite Numbers
This example checks a list of 12 numbers of various lengths and filters all numbers that are not prime (that is, it returns all composites).
4413061 1231 839791 123456789 17 287500711 857663 987654321 311 13579 30762001 97531
123456789 987654321 13579 97531
Required options
These options will be used automatically if you select this example.
Show only numbers that are сomposite.
Pro tips Master online number tools
You can pass input to this tool via ?input query argument and it will automatically compute output. Here's how to type it in your browser's address bar. Click to try!
https://onlinenumbertools.com/number-primality-test?input=1%0A3%0A5%0A7%0A9%0A11%0A13%0A15%0A17%0A19&test-all-numbers=true
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Quickly create a list of increasing or decreasing integers.
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Quickly create a sequence of odd numbers.
Quickly choose one or more numbers from a list of numbers.
Quickly sort numbers in ascending or descending order.
Quickly filter numbers according to certain criteria.
Quickly add up all the numbers in the given list and find their sum.
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Generate Natural Numbers
Create a list of natural numbers.
Generate Rational Numbers
Create a list of rational numbers.
Generate Real Numbers
Create a sequence of real numbers.
Generate Complex Numbers
Create a list of complex numbers.
Generate Binary Numbers
Create a sequence of binary numbers.
Generate Powers of 2
Create a list of numbers that are powers of two.
Generate Powers of 10
Create a list of numbers that are powers of ten.
Generate Pairs of Numbers
Create a sequence of number pairs.
Create a Floating Point Number
Create a fp from the significand, base and exponent.