# Modular inverse

This English edition is an AI candidate and does not yet have an OCME Atlas (GPT-6) Twin closure receipt.

[Catalogue presentation and source-binding data](https://ocme.evemisslab.com/data/i18n/catalogue.en.json)



## [Modular inverse](https://ocme.evemisslab.com/en/atlas/atlas-modular-inverse/)

For n≥2, a has a multiplicative inverse modulo n exactly when gcd(a,n)=1; the inverse is unique as a residue class modulo n.

atlas-modular-inverse · canonical_mko

[Modular inverse](https://ocme.evemisslab.com/en/mko/mko-modular-inverse/)

## Prerequisite nodes


- [Greatest common divisor and coprimality](https://ocme.evemisslab.com/en/atlas/atlas-gcd-coprime/)
- [Natural-number congruence modulo a positive modulus](https://ocme.evemisslab.com/en/atlas/atlas-modular-congruence/)
- [Equation](https://ocme.evemisslab.com/en/atlas/atlas-equation/)