---
tag: 0DZXAXEJQ9
kind: concept
name: Irrational number
msc: [11J72]
sources:
  - url: https://en.wikipedia.org/wiki/Irrational_number
    locator: lead section
same_as:
  wikidata: Q607728
  wikipedia: Irrational number
---

## Summary

An irrational number is a [[real number|08J2M1JYAG]] that is not a [[rational number|0NCJ5WXN6Z]].
Examples are $\sqrt{2}$, $\pi$ and $e$.