iPhone Screenshots


Primes, Prime Factors

This app lets you
• check numbers to see if they are prime numbers,
• find next prime,
• find primes within an interval (range), and
• determining prime factors.
The input numbers need be between 0 and 9,223,372,036,854,775,807, which is 2^63-1, or approximately 9.223·10^18. Just keep numbers less than 19 digits; a validation mechanism prevents illegal input.

A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. Examples: 2, 3, 5, 7, 11, 13, 17. 2 is the only even prime.
When finding primes in an interval, duration is shown, so the app may be used for benchmarking as well.

Prime factor
A natural number greater than 1 that is not a prime number is called a composite number. Enter any number into the Factor field, to get its prime factors. If the number is a prime, then it has only one factor, itself.
•Entering 6, gives 2 3.
•Entering 12, gives 2 2 3.
•Entering 100, gives 2 2 5 5.
Since very big numbers may consist of many small primes, prime factorization of large numbers may be very quick. Try it out.
Duration is shown.

I have tried to translate this app into every language imaginable, but I have used an online translation service for most of them, and as you know, words may have different meanings.
Please do not hesitate to email me, if you have any corrections to the translations, or just any tips or criticism to this app. I will read every mail — if it is written in English :)

What’s New

Version 1.3.2


Ratings and Reviews

4.1 out of 5
13 Ratings

13 Ratings

The Meerkat ,

Clean and simple

Does numbers up to 2^64.
Has nice extras like next prime and primes in a range. Easy to use. Simple useful output. Needs a previous prime function. Great app that gets the job done

msngy ,

Love it

It's a simple but effective app. Helps me with my child home work.


Henning Poulsen
1.7 MB

Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.


English, Arabic, Catalan, Croatian, Czech, Danish, Dutch, Faeroese, Finnish, French, German, Greek, Hebrew, Hungarian, Icelandic, Indonesian, Italian, Japanese, Korean, Malay, Norwegian Bokmål, Polish, Portuguese, Romanian, Russian, Simplified Chinese, Slovak, Spanish, Swedish, Thai, Traditional Chinese, Turkish, Ukrainian, Vietnamese

Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

More By This Developer

You May Also Like