# Primality — Integer Primality or Factors > Determines primality or prime factors of integers, with prime ordinality calculation. (iPhone/iPad app by Bruce Schechter.) - Source: https://appshunter.io/ios/app/primality/id1516003672 (this page in markdown: same URL + `.md`) - Developer: [Bruce Schechter](https://appshunter.io/developer/1515359087) - Category: Utilities, Reference - Price: Free - Rating: 4.88/5 from 24 App Store ratings · 8 written reviews indexed - Age rating: 4+ - Requires: iOS 13.2 · 1 MB - Languages: English - Released: 2020-06-15 - Data updated: 2026-09-09 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/primality/id1516003672/reviews.md ## What is Primality? The Primality App has a clean and simple, yet powerful, function: Given any integer, the app determines either that the given integer is prime or else it provides all prime factors of that integer. Very clean, very simple, focussed. The app operates in the range of 0 - 999,999,999,999. A popular feature of the app is its ability to determine the prime ordinality of each prime found, such as observing that 97 if the 25th prime. (However, this particular feature is available only up to the 100,000th prime, which is 1,299,709.) Requires iOS 13 or higher. ## Key features - Primality testing - Prime factorization - Prime ordinality calculation - Large integer support (up to 999,999,999,999) - Clean and simple interface ## Recent user reviews (8 of 8) All indexed reviews: https://appshunter.io/ios/app/primality/id1516003672/reviews.md ### 5/5 — Fulfills your prime number curiosity *2020-07-01, version 0.14* This is a great app with a streamlined interface to answer the question that comes up surprisingly often in random conversation: is this number a prime? Nice features to answer that question and show the factors if it’s not prime, or tell you which n-th prime number it is. I see a fun car game with the kids in the future! ### 5/5 — Good App *2020-06-25, version 0.14* Clean and quick, instant results. Primes and Factors. ### 5/5 — Super fast factoring of numbers *2020-06-22, version 0.14* Are you one of the numerical geeky sorts who likes primes? This is a fun tool to show you the factors of a number or whether it’s a prime number. Can’t say it’s useful but it’s a clean interface, simple and fun to check even really large numbers. ### 5/5 — Found a five digit prime number *2020-06-22, version 0.14* Nice program to determine if a number is prime. I’m waiting for the vision addition where I take a picture of the number and it indicates prime or not prime. ### 5/5 — Best prime number app I’ve ever used *2020-06-19, version 0.14* 👍👍!!! Definitely worth the price ### 5/5 — Very clean app, with great usability and performance. *2020-06-18, version 0.14* The UI for this prime number app is completely intuitive, and set up to allow easy exploration of the region of any number. The performance is startlingly good. ### 4/5 — Let’s gamify it! *2020-06-18, version 0.14* Very cool to test your mathematical recall skills. Would love some “game modes” that give you some numbers inside of bubbles or balloons an you have to pop the ones with prime numbers. Accelerate speed as you progress. Maybe a quiz mode that starts at a random number and you have a time limit for entering the next five prime numbers in order. Difficulty could be determined based on how large a number you start with. ### 5/5 — We really enjoyed this app BUT *2020-06-15, version 0.14* My wife likes it BUT thinks it should produce fireworks if the user finds any prime numbers of at least 5 digits! ## Frequently asked questions about Primality ### What is the maximum integer Primality can check? Primality can operate on integers in the range of 0 to 999,999,999,999. This extensive range allows for the analysis of very large numbers. ### Does Primality show the position of prime numbers? Yes, a popular feature is its ability to determine the prime ordinality of each prime found, such as identifying 97 as the 25th prime. This feature is available up to the 100,000th prime. ### What devices does Primality support? Primality is designed for iOS devices, specifically supporting the iPhone and iPod. It requires iOS 13 or higher. ### How often is Primality updated? The app was last updated on August 2, 2020, with version 1.00. It was initially released on June 15, 2020. ### What is the age rating for Primality? Primality has an age rating of 4+, making it suitable for a wide range of users interested in its mathematical functions. ### Is Primality free to use? Yes, Primality is available for free. There are no in-app purchases or advertisements, offering a straightforward user experience. ### What makes Primality stand out from other math apps? Primality focuses specifically on primality testing and prime factorization with a clean, powerful, and simple interface. Its ability to calculate prime ordinality is a unique feature. ### What do users think of Primality? Users have rated Primality highly, with an average of 4.9 stars from 24 ratings, indicating strong satisfaction with its functionality and performance. ## Version history (last 2 releases) ### 1.00 — 2020-08-02 Minor UI improvements ### 0.14 — 2020-06-15 No release notes. ## Apps similar to Primality | App | Rating | Price | Category | | --- | --- | --- | --- | | [TBM 910 Interior](https://appshunter.io/ios/app/tbm-910-interior/id869415980) | 5.0 (2) | Free | Utilities | | [句子迷](https://appshunter.io/ios/app/id884715640) | 3.9 (8) | Free | Utilities | | [mDNS Utility](https://appshunter.io/ios/app/mdns-utility/id918208340) | 1.6 (5) | $0.99 | Utilities | | [Meck Sheriff](https://appshunter.io/ios/app/meck-sheriff/id917682360) | — | Free | Utilities | | [Send Smart](https://appshunter.io/ios/app/send-smart/id912763740) | 2.2 (10) | Free | Utilities | | [i Sound Level Meter](https://appshunter.io/ios/app/i-sound-level-meter/id912170360) | 4.4 (37) | Free | Utilities | ## Related topics [6144](https://appshunter.io/ios/topics/6144) · [7353](https://appshunter.io/ios/topics/7353) · [prime factorization factorizer](https://appshunter.io/ios/topics/prime-factorization-factorizer) --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-09.*