# Prime Checker vs Prime Factors

The clearest difference is price: Prime Checker at Free against Prime Factors's $0.99. Prime Checker also leads on rating (5.0 vs 3.9) and review sentiment (96% vs 79%). Prime Factors's advantage is ratings volume (24 vs 3). On update cadence, ads, in-app purchases and monetization model there is nothing between them.

Prime Checker is free to download; Prime Factors costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Prime Checker holds the better App Store score, 5.0 against 3.9. That said, the two scores are not equally well evidenced: Prime Factors has 24 ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 96% of Prime Checker's written reviews are positive against 79% of Prime Factors's.

Prime Checker ships an update every 17 months, Prime Factors every 21 months. The most recent releases landed on September 29, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Prime Checker | Prime Factors |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | **[5.0 (3 ratings)](https://appshunter.io/ios/app/prime-checker/id389112910/reviews)** | [3.9 (24 ratings)](https://appshunter.io/ios/app/prime-factors/id741746948/reviews) |
| Number of ratings | 3 | **24** |
| Positive reviews | **95.8% of reviews** | 78.6% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 17 months** | Every 21 months |
| Monetization | Free | Free |
| Size | 3 MB | 1 MB |
| Requires iOS | **12.4** | 18.0 |
| Devices | **iPhone, iPad, iPod, Apple Watch** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Heart Solutions, Inc.](https://appshunter.io/developer/389112913) | [Paul Hangas](https://appshunter.io/developer/433121902) |

## 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


### Prime Factors

[App page](https://appshunter.io/ios/app/prime-factors/id741746948)

Explore numbers up to one trillion, with primes clearly marked. Tap any number to reveal its prime factors. Easily navigate to specific numbers using the search function and adjust the display with pinch-to-zoom gestures.

**Highlights:** View numbers up to 1 trillion, Prime numbers highlighted, Tap for prime factors, Search for specific numbers, Pinch and zoom display

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Prime Checker free?

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

### Is Prime Factors free?

Prime Factors costs $0.99, with no in-app purchases.

### Which has better reviews, Prime Checker or Prime Factors?

Prime Checker is rated higher. Prime Checker averages 5.0 out of 5 from 3 ratings, while Prime Factors averages 3.9 from 24 ratings.

### Do Prime Checker or Prime Factors have ads?

Neither Prime Checker nor Prime Factors shows ads.

### Which is updated more often, Prime Checker or Prime Factors?

Prime Checker ships an update every 17 months, and Prime Factors every 21 months. Most recently, Prime Checker was updated on September 29, 2026 and Prime Factors on October 24, 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.*