calcMod vs Prime Not Prime
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
calcMod
This application helps users perform complex mathematical calculations, including factorials, primality tests, and modular arithmetic. It's designed for students and educators interested in number theory and the properties of integers.
- Factorial calculation up to 80!
- Primality testing with change mod function
- Divisor identification
- Modular exponentiation
- Modular inverse calculation
- Number storage and recall
Read full descriptionHide full description
What are all the digits of the factorial of 79 and how many digits ? Want to know if a big integer is prime ? The change mod function indicates when the number is prime. Want to know the divisors of an integer ? A prime divisor has no inverse modulo this integer. The "n!" button calculates the factorial of an integer from 0 to 80. Factorial are limited to factorial of 80, but the calculator could calculate them up to 2000 ! (ProX version) The "change mod" (change modulo) function indicates when the modulo is prime. There is a limit to 10^10 for modulo in this FREE version (no limit with ProX version). You can stoke one number and recall it when you want. The "Mod" operation indicates the residue modulo N. The exp function allow modular exponentiation (as + - *) The "INV" function calculates the inverse of an integer modulo N. This app is intended for both mathematics teachers and/or their students, or if you are interested in the beauty of numbers. Enjoy calcMod-Light ! Les commentaires sont disponibles en français (réglages).
Prime Not Prime
A fast-paced game that combines number recognition with a swiping mechanic. Players swipe right for prime numbers and left for non-primes, aiming to build long streaks. It's designed to be both educational and entertaining, with leaderboards for competitive play.
- Addictive swiping gameplay
- Test prime number knowledge
- Build streaks and complete challenges
- Global leaderboards
- Vibrant visuals and animations
Read full descriptionHide full description
Ready to swipe your way to prime number mastery? Prime Not Prime is the fun, fast-paced game where math meets swiping! Like Tinder for numbers, you swipe right for primes and left for everything else. Easy to learn, but can you handle the streak pressure? Features You’ll Love: • Addictive Swiping Gameplay: Swipe numbers left or right in a race against time. • Test Your Knowledge: Spot prime numbers and learn fun math facts. • Streaks and Challenges: Compete to see how long you can keep your streak alive. • Leaderboards: Challenge friends and global players to see who’s the prime master. • Widgets: Guess your prime numbers right from your Home Screen. • Fun Design: Vibrant visuals and satisfying animations make every swipe exciting. Whether you’re a math whiz or just love a challenge, Prime Not Prime is the ultimate game for your brain. Swipe, learn, and have fun with prime numbers! Privacy Policy & Terms: https://www.rspoon3.com/prime-not-prime/privacy/
Screenshots
Verdict
The clearest difference is rating: calcMod at 5.0 against Prime Not Prime's 4.3. calcMod also leads on iOS requirement (15.0 vs 17.0). Prime Not Prime's advantage is update cadence (monthly vs every 18 months) and ratings volume (6 vs 1). On price, review sentiment, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
calcMod holds the better App Store score, 5.0 against 4.3. That said, the two scores are not equally well evidenced: Prime Not Prime has 6 ratings behind it against 1, so its average is the more settled of the two. Written reviews split almost evenly too, at 100% and 100% positive.
calcMod ships an update every 18 months, Prime Not Prime monthly. The most recent releases landed on October 26, 2026 and October 30, 2026 respectively.
| Parameter | calcMod | Prime Not Prime |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) — better | 4.3 (6 ratings) |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 1 | 6 — better |
| Update frequency | Every 18 months | Monthly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPod — better | iPhone |
| Requires iOS | 15.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 1 MB | 15 MB |
| Age rating | 4+ | 4+ |
| Developer | Alain Cardinaux | Richard Witherspoon |
Customer experience
calcMod
Prime Not Prime
In-app purchases
calcMod
No in-app purchases
Prime Not Prime
No in-app purchases
Questions
Is calcMod free?
Is Prime Not Prime free?
Which has better reviews, calcMod or Prime Not Prime?
Do calcMod or Prime Not Prime have ads?
Which is updated more often, calcMod or Prime Not Prime?
Other comparisons
