Prime Factors vs PFD Calc
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Prime Factors
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.
- View numbers up to 1 trillion
- Prime numbers highlighted
- Tap for prime factors
- Search for specific numbers
- Pinch and zoom display
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View all numbers from 1 to 1,000,000,000,000. Prime numbers shown with a red circle. Tap a number to see its Prime Factors. Jump directly to a number with the search field. • Prime Numbers are marked with a red circle • Prime Factors can be viewed by tapping on a number • Pinch and Zoom to change the number of columns
PFD Calc
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The app calculates prime factorization.
Screenshots
Verdict
The clearest difference is price: PFD Calc at Free against Prime Factors's $0.99. PFD Calc also leads on update cadence (every 5 weeks vs every 21 months) and iOS requirement (15.0 vs 18.0). Prime Factors's advantage is ads (none vs shown). On in-app purchases and device support 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
PFD Calc 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 Factors ships an update every 21 months, PFD Calc every 5 weeks. The most recent releases landed on September 10, 2026 and September 17, 2026 respectively.
| Parameter | Prime Factors | PFD Calc |
|---|---|---|
| Price | $0.99 | Free — better |
| Rating | 3.9 (24 ratings) — better | — |
| Positive reviews | 78.6% of reviews | — |
| Number of ratings | 24 — better | — |
| Update frequency | Every 21 months | Every 5 weeks — better |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 18.0 | 15.0 — better |
| Further details — not scored | ||
| Size | 1 MB | 14 MB |
| Age rating | 4+ | 4+ |
| Developer | Paul Hangas | Kazuhisa Kobayashi |
In-app purchases
Prime Factors
No in-app purchases
PFD Calc
No in-app purchases
Questions
Is Prime Factors free?
Is PFD Calc free?
Do Prime Factors or PFD Calc have ads?
Which is updated more often, Prime Factors or PFD Calc?
Other comparisons
