# Prime Checker vs PFD Calc

The clearest difference is ads: Prime Checker at none against PFD Calc's shown. Prime Checker also leads on iOS requirement (12.4 vs 15.0). PFD Calc's advantage is update cadence (every 5 weeks vs every 17 months). On price, in-app purchases and device support there is nothing between them.

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

Prime Checker ships an update every 17 months, PFD Calc every 5 weeks. The most recent releases landed on August 29, 2026 and September 17, 2026 respectively.

## The numbers

| Metric | Prime Checker | PFD Calc |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (3 ratings)](https://appshunter.io/ios/app/prime-checker/id389112910/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 95.8% of reviews | — |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 17 months | **Every 5 weeks** |
| Monetization | Free | — |
| Size | 3 MB | 14 MB |
| Requires iOS | **12.4** | 15.0 |
| Devices | **iPhone, iPad, iPod, Apple Watch** | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Heart Solutions, Inc.](https://appshunter.io/developer/389112913) | [Kazuhisa Kobayashi](https://appshunter.io/developer/1580882000) |

## 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


### PFD Calc

[App page](https://appshunter.io/ios/app/pfd-calc-prime-factorization/id6737405828)

**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 PFD Calc free?

PFD Calc is free to download, with no in-app purchases.

### Do Prime Checker or PFD Calc have ads?

PFD Calc shows ads; Prime Checker does not.

### Which is updated more often, Prime Checker or PFD Calc?

Prime Checker ships an update every 17 months, and PFD Calc every 5 weeks. Most recently, Prime Checker was updated on August 29, 2026 and PFD Calc on September 17, 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.*