Properties

Label 21.21.5778662528...5689.1
Degree $21$
Signature $[21, 0]$
Discriminant $3^{28}\cdot 43^{18}$
Root discriminant $108.71$
Ramified primes $3, 43$
Class number $1$ (GRH)
Class group Trivial (GRH)
Galois group $C_{21}$ (as 21T1)

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![251, 18912, -66246, -495851, 2597691, -3157635, -1893950, 6238701, -2337081, -3001988, 2251605, 440313, -717609, 38604, 107772, -17502, -7923, 1785, 262, -72, -3, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^21 - 3*x^20 - 72*x^19 + 262*x^18 + 1785*x^17 - 7923*x^16 - 17502*x^15 + 107772*x^14 + 38604*x^13 - 717609*x^12 + 440313*x^11 + 2251605*x^10 - 3001988*x^9 - 2337081*x^8 + 6238701*x^7 - 1893950*x^6 - 3157635*x^5 + 2597691*x^4 - 495851*x^3 - 66246*x^2 + 18912*x + 251)
 
gp: K = bnfinit(x^21 - 3*x^20 - 72*x^19 + 262*x^18 + 1785*x^17 - 7923*x^16 - 17502*x^15 + 107772*x^14 + 38604*x^13 - 717609*x^12 + 440313*x^11 + 2251605*x^10 - 3001988*x^9 - 2337081*x^8 + 6238701*x^7 - 1893950*x^6 - 3157635*x^5 + 2597691*x^4 - 495851*x^3 - 66246*x^2 + 18912*x + 251, 1)
 

Normalized defining polynomial

\( x^{21} - 3 x^{20} - 72 x^{19} + 262 x^{18} + 1785 x^{17} - 7923 x^{16} - 17502 x^{15} + 107772 x^{14} + 38604 x^{13} - 717609 x^{12} + 440313 x^{11} + 2251605 x^{10} - 3001988 x^{9} - 2337081 x^{8} + 6238701 x^{7} - 1893950 x^{6} - 3157635 x^{5} + 2597691 x^{4} - 495851 x^{3} - 66246 x^{2} + 18912 x + 251 \)

magma: DefiningPolynomial(K);
 
sage: K.defining_polynomial()
 
gp: K.pol
 

Invariants

Degree:  $21$
magma: Degree(K);
 
sage: K.degree()
 
gp: poldegree(K.pol)
 
Signature:  $[21, 0]$
magma: Signature(K);
 
sage: K.signature()
 
gp: K.sign
 
Discriminant:  \(5778662528422377251527626979988196021835689=3^{28}\cdot 43^{18}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $108.71$
magma: Abs(Discriminant(Integers(K)))^(1/Degree(K));
 
sage: (K.disc().abs())^(1./K.degree())
 
gp: abs(K.disc)^(1/poldegree(K.pol))
 
Ramified primes:  $3, 43$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois and abelian over $\Q$.
Conductor:  \(387=3^{2}\cdot 43\)
Dirichlet character group:    $\lbrace$$\chi_{387}(256,·)$, $\chi_{387}(1,·)$, $\chi_{387}(130,·)$, $\chi_{387}(259,·)$, $\chi_{387}(4,·)$, $\chi_{387}(133,·)$, $\chi_{387}(262,·)$, $\chi_{387}(385,·)$, $\chi_{387}(64,·)$, $\chi_{387}(322,·)$, $\chi_{387}(16,·)$, $\chi_{387}(145,·)$, $\chi_{387}(274,·)$, $\chi_{387}(97,·)$, $\chi_{387}(226,·)$, $\chi_{387}(355,·)$, $\chi_{387}(193,·)$, $\chi_{387}(121,·)$, $\chi_{387}(250,·)$, $\chi_{387}(379,·)$, $\chi_{387}(127,·)$$\rbrace$
This is not a CM field.

Integral basis (with respect to field generator \(a\))

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $\frac{1}{7} a^{15} + \frac{1}{7} a^{14} - \frac{2}{7} a^{13} - \frac{3}{7} a^{12} - \frac{2}{7} a^{11} + \frac{1}{7} a^{10} + \frac{2}{7} a^{9} - \frac{2}{7} a^{8} + \frac{2}{7} a^{7} - \frac{2}{7} a^{6} + \frac{2}{7} a^{5} + \frac{2}{7} a^{3} - \frac{3}{7} a^{2} - \frac{2}{7} a + \frac{2}{7}$, $\frac{1}{7} a^{16} - \frac{3}{7} a^{14} - \frac{1}{7} a^{13} + \frac{1}{7} a^{12} + \frac{3}{7} a^{11} + \frac{1}{7} a^{10} + \frac{3}{7} a^{9} - \frac{3}{7} a^{8} + \frac{3}{7} a^{7} - \frac{3}{7} a^{6} - \frac{2}{7} a^{5} + \frac{2}{7} a^{4} + \frac{2}{7} a^{3} + \frac{1}{7} a^{2} - \frac{3}{7} a - \frac{2}{7}$, $\frac{1}{7} a^{17} + \frac{2}{7} a^{14} + \frac{2}{7} a^{13} + \frac{1}{7} a^{12} + \frac{2}{7} a^{11} - \frac{1}{7} a^{10} + \frac{3}{7} a^{9} - \frac{3}{7} a^{8} + \frac{3}{7} a^{7} - \frac{1}{7} a^{6} + \frac{1}{7} a^{5} + \frac{2}{7} a^{4} + \frac{2}{7} a^{2} - \frac{1}{7} a - \frac{1}{7}$, $\frac{1}{259} a^{18} + \frac{8}{259} a^{17} - \frac{4}{259} a^{16} - \frac{2}{259} a^{15} + \frac{68}{259} a^{14} - \frac{13}{259} a^{13} - \frac{52}{259} a^{12} + \frac{39}{259} a^{11} - \frac{69}{259} a^{10} - \frac{41}{259} a^{9} - \frac{29}{259} a^{8} - \frac{88}{259} a^{7} + \frac{118}{259} a^{6} - \frac{25}{259} a^{5} + \frac{1}{259} a^{4} - \frac{2}{37} a^{3} - \frac{61}{259} a^{2} + \frac{25}{259} a + \frac{27}{259}$, $\frac{1}{259} a^{19} + \frac{6}{259} a^{17} - \frac{1}{37} a^{16} + \frac{10}{259} a^{15} - \frac{113}{259} a^{14} + \frac{18}{37} a^{13} - \frac{9}{37} a^{12} + \frac{9}{37} a^{11} + \frac{67}{259} a^{10} + \frac{3}{259} a^{9} - \frac{78}{259} a^{8} + \frac{8}{259} a^{7} - \frac{1}{37} a^{6} - \frac{58}{259} a^{5} + \frac{52}{259} a^{4} + \frac{88}{259} a^{3} + \frac{69}{259} a^{2} + \frac{12}{259} a - \frac{15}{37}$, $\frac{1}{32150934052884446784525141950738152033910521} a^{20} + \frac{20011761867310078764086123860907492259033}{32150934052884446784525141950738152033910521} a^{19} + \frac{44755235088556389352232322407153927193397}{32150934052884446784525141950738152033910521} a^{18} - \frac{71468685398735175689947736450717503745970}{4592990578983492397789305992962593147701503} a^{17} + \frac{5665887946806777826522379576940689561998}{868944163591471534716895728398328433348933} a^{16} + \frac{1032601348363763847497696951630977853094190}{32150934052884446784525141950738152033910521} a^{15} - \frac{11192621643465453023031850996594250917448783}{32150934052884446784525141950738152033910521} a^{14} + \frac{5882564682874840704856948923078799116428018}{32150934052884446784525141950738152033910521} a^{13} + \frac{14118220301851052519482625780496948241543473}{32150934052884446784525141950738152033910521} a^{12} - \frac{12282557587302134183910095678515257433939065}{32150934052884446784525141950738152033910521} a^{11} + \frac{13375333880529023098350527313659460279517036}{32150934052884446784525141950738152033910521} a^{10} - \frac{8936648697948973741272001907570095973162753}{32150934052884446784525141950738152033910521} a^{9} - \frac{13272073365237331946300797872344198030044930}{32150934052884446784525141950738152033910521} a^{8} + \frac{11523434967271330469027722306474536817353043}{32150934052884446784525141950738152033910521} a^{7} + \frac{273948571575666313749087433344639539782247}{4592990578983492397789305992962593147701503} a^{6} - \frac{9378287354337518915727500615325553857319729}{32150934052884446784525141950738152033910521} a^{5} - \frac{1347945709658695405077741680412244719106015}{4592990578983492397789305992962593147701503} a^{4} + \frac{6006148198863892284495168192632910077783757}{32150934052884446784525141950738152033910521} a^{3} + \frac{2335544878640766323764541903580233093007447}{32150934052884446784525141950738152033910521} a^{2} + \frac{1900429616477932613550323777334379996263487}{4592990578983492397789305992962593147701503} a - \frac{13496987488554564300929578064666754069325644}{32150934052884446784525141950738152033910521}$

magma: IntegralBasis(K);
 
sage: K.integral_basis()
 
gp: K.zk
 

Class group and class number

Trivial group, which has order $1$ (assuming GRH)

magma: ClassGroup(K);
 
sage: K.class_group().invariants()
 
gp: K.clgp
 

Unit group

magma: UK, f := UnitGroup(K);
 
sage: UK = K.unit_group()
 
Rank:  $20$
magma: UnitRank(K);
 
sage: UK.rank()
 
gp: K.fu
 
Torsion generator:  \( -1 \) (order $2$)
magma: K!f(TU.1) where TU,f is TorsionUnitGroup(K);
 
sage: UK.torsion_generator()
 
gp: K.tu[2]
 
Fundamental units:  Units are too long to display, but can be downloaded with other data for this field from 'Stored data to gp' link to the right (assuming GRH)
magma: [K!f(g): g in Generators(UK)];
 
sage: UK.fundamental_units()
 
gp: K.fu
 
Regulator:  \( 520470899652557.25 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

$C_{21}$ (as 21T1):

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A cyclic group of order 21
The 21 conjugacy class representatives for $C_{21}$
Character table for $C_{21}$ is not computed

Intermediate fields

\(\Q(\zeta_{9})^+\), 7.7.6321363049.1

Fields in the database are given up to isomorphism. Isomorphic intermediate fields are shown with their multiplicities.

Frobenius cycle types

$p$ 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59
Cycle type $21$ R $21$ ${\href{/LocalNumberField/7.3.0.1}{3} }^{7}$ $21$ $21$ ${\href{/LocalNumberField/17.7.0.1}{7} }^{3}$ ${\href{/LocalNumberField/19.7.0.1}{7} }^{3}$ $21$ $21$ $21$ ${\href{/LocalNumberField/37.1.0.1}{1} }^{21}$ $21$ R $21$ ${\href{/LocalNumberField/53.7.0.1}{7} }^{3}$ $21$

In the table, R denotes a ramified prime. Cycle lengths which are repeated in a cycle type are indicated by exponents.

magma: p := 7; // to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$:
 
magma: idealfactors := Factorization(p*Integers(K)); // get the data
 
magma: [<primefactor[2], Valuation(Norm(primefactor[1]), p)> : primefactor in idealfactors];
 
sage: p = 7; # to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$:
 
sage: [(e, pr.norm().valuation(p)) for pr,e in K.factor(p)]
 
gp: p = 7; \\ to obtain a list of $[e_i,f_i]$ for the factorization of the ideal $p\mathcal{O}_K$:
 
gp: idealfactors = idealprimedec(K, p); \\ get the data
 
gp: vector(length(idealfactors), j, [idealfactors[j][3], idealfactors[j][4]])
 

Local algebras for ramified primes

$p$LabelPolynomial $e$ $f$ $c$ Galois group Slope content
3Data not computed
43Data not computed