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Primes and Prime Factors App app for iPhone and iPad


4.2 ( 1712 ratings )
Utilities Education
Developer: Henning Poulsen
Free
Current version: 1.3.2, last update: 6 years ago
First release : 17 Jan 2014
App size: 1.58 Mb

Primes, Prime Factors

About
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.

Primes
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.
Examples:
•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.



Localization/Translation
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 :)

Pros and cons of Primes and Prime Factors App app for iPhone and iPad

Primes and Prime Factors App app good for

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
Its a simple but effective app. Helps me with my child home work.

Some bad moments