# Sosu der — ～素数クイズ～

> ～素数クイズ～ (iPhone/iPad app by Hirobumi Onishi.)

- Source: https://appshunter.io/ios/app/sosu-der/id6483364985 (this page in markdown: same URL + `.md`)
- Developer: [Hirobumi Onishi](https://appshunter.io/developer/1740115066)
- Category: Games, Education, Casual, Puzzle
- Price: Free
- Age rating: 4+
- Requires: iOS 15.0 · 140 MB
- Languages: American English
- Released: 2024-05-16
- Data updated: 2026-08-05
- User reviews in markdown: https://appshunter.io/ios/app/sosu-der/id6483364985/reviews.md

## What is Sosu der?

This app is a quiz application that determines whether a number is prime or composite and swipes the correct answer.

A prime number is a natural number greater than 1 that is not divisible by any other number except 1 and the number itself. For example, 2, 3, 5, and 7 are single-digit prime numbers.

Composite numbers (composite numbers) are natural numbers greater than 1 that are not prime and are represented by the product of smaller natural numbers (e.g., 4 = 2 x 2, 6 = 2 x 3).

Through this app, you can test your judgment and reflexes while having fun learning these mathematical concepts.


... How many two-digit, three-digit, and four-digit prime numbers do you know?

Translated with www.DeepL.com/Translator (free version)


## Version history (last 4 releases)

### 1.3 — 2026-08-02

Improved app stability and updated the advertising system.
Added access to the Privacy Policy from the Settings screen.

### 1.2 — 2024-10-03

Stability improvements and bug fixes.
Performance Metrics Feature: We have added a performance metrics feature to ensure the healthy operation of the app.
Unlock Catalog Items through Ad Viewing: Now you can unlock additional catalog items by viewing ads.
Local Notifications: We have introduced local notifications to keep you informed and up to date with important app events.
This update aims to enhance user experience and improve the app's overall performance. We are committed to ensuring that the app functions optimally while maintaining a healthy environment for all users.

### 1.1 — 2024-05-21

Stability improvements and bug fixes.

### 1.0 — 2024-05-16

No release notes.

## Apps similar to Sosu der

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Zombie Puzzle Color Sort Game](https://appshunter.io/ios/app/zombie-puzzle-color-sort-game/id6477746949) | — | Free | Games |
| [97 – Prime Number Puzzle](https://appshunter.io/ios/app/97-prime-number-puzzle/id6475675534) | — | Free | Games |
| [2357P](https://appshunter.io/ios/app/2357p/id957233368) | 3.0 (2) | Free | Games |
| [Prime Pick](https://appshunter.io/ios/app/prime-pick/id6502471694) | — | Free | Games |
| [PrimePath](https://appshunter.io/ios/app/primepath/id6449695255) | — | Free | Games |
| [ThePrimes](https://appshunter.io/ios/app/theprimes/id418752919) | — | Free | Games |

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-05.*