# Prime Checker vs 3n or Not

The clearest difference is ads: Prime Checker at none against 3n or Not's shown. Prime Checker also leads on monetization model (free vs ad-supported) and iOS requirement (12.4 vs 14.0). 3n or Not's advantage is update cadence (every 4 months vs every 17 months). On price, rating, review sentiment and ratings volume there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 5.0 for Prime Checker against 5.0 for 3n or Not. Both are backed by a comparable volume of ratings — 3 and 3 respectively. Written reviews split almost evenly too, at 96% and 95% positive.

Prime Checker ships an update every 17 months, 3n or Not every 4 months. The most recent releases landed on November 1, 2026 and November 6, 2026 respectively.

## The numbers

| Metric | Prime Checker | 3n or Not |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (3 ratings)](https://appshunter.io/ios/app/prime-checker/id389112910/reviews) | [5.0 (3 ratings)](https://appshunter.io/ios/app/3n-or-not/id913003589/reviews) |
| Number of ratings | 3 | 3 |
| Positive reviews | **95.8% of reviews** | 95.5% of reviews |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 17 months | **Every 4 months** |
| Monetization | **Free** | Ad-supported |
| Size | 3 MB | 13 MB |
| Requires iOS | **12.4** | 14.0 |
| Devices | **iPhone, iPad, iPod, Apple Watch** | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Heart Solutions, Inc.](https://appshunter.io/developer/389112913) | [Ninicode](https://appshunter.io/developer/647989501) |

## What reviewers say

### Prime Checker

[App page](https://appshunter.io/ios/app/prime-checker/id389112910)

This app performs advanced mathematical calculations for numbers, including integer factorization, Euler's totient function, and solving specific Diophantine equations. It utilizes advanced algorithms for factorization and primality testing.

**Highlights:** Integer factorization, Euler's totient function, Primitive root calculation, Diophantine equation solver, Primality testing

**Features:** macOS Compatibility

**In-app purchases:** none


### 3n or Not

[App page](https://appshunter.io/ios/app/3n-or-not/id913003589)

Test your quick thinking with this educational game.  It challenges you to rapidly identify if a given number is divisible by three. Perfect for practicing mental math skills.

**Highlights:** Quick number discrimination, Multiple of 3 identification, Mental math practice, Educational game

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Prime Checker free?

Prime Checker is free to download, with no in-app purchases.

### Is 3n or Not free?

3n or Not is free to download, with no in-app purchases.

### Which has better reviews, Prime Checker or 3n or Not?

Prime Checker and 3n or Not are both rated 5.0 out of 5 on the App Store, from 3 and 3 ratings respectively.

### Do Prime Checker or 3n or Not have ads?

3n or Not shows ads; Prime Checker does not.

### Which is updated more often, Prime Checker or 3n or Not?

Prime Checker ships an update every 17 months, and 3n or Not every 4 months. Most recently, Prime Checker was updated on November 1, 2026 and 3n or Not on November 6, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*