PrimitiveRoot

PrimitiveRoot[n]

gives a primitive root of n.

PrimitiveRoot[n,k]

gives the smallest primitive root of n greater than or equal to k.

Details

  • PrimitiveRoot[n] gives a generator for the multiplicative group of integers modulo n relatively prime to n.
  • PrimitiveRoot[n] returns unevaluated if n is not 2, 4, an odd prime power, or twice an odd prime power.
  • PrimitiveRoot[n,1] computes the smallest primitive root of n.

Examples

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Basic Examples  (2)

A primitive root of 9 is 2:

The primitive root generates all integers modulo 9 that are relatively prime to 9:

A primitive root of 10:

The smallest primitive root of 10:

Scope  (3)

Find the smallest primitive root:

Find the primitive root greater than a number:

PrimitiveRoot works on large integers:

PrimitiveRoot automatically threads over lists:

Properties & Relations  (2)

The multiplicative order of a primitive root modulo n is EulerPhi[n]:

For a prime p, there exist EulerPhi[p-1] primitive roots modulo p:

Possible Issues  (1)

PrimitiveRoot is not defined for all integers:

Neat Examples  (1)

Elements relatively prime to 22 are enumerated by the primitive root:

Introduced in 2007
 (6.0)
 |
Updated in 2015
 (10.3)