Properties

Label 21.21.1038187830...8329.1
Degree $21$
Signature $[21, 0]$
Discriminant $7^{38}\cdot 19^{14}$
Root discriminant $240.84$
Ramified primes $7, 19$
Class number $3$ (GRH)
Class group $[3]$ (GRH)
Galois group $C_{21}$ (as 21T1)

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magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![12861176609, 11414547333, -96402059663, -206563651595, -72622185076, 180231411857, 227577402612, 95156654696, -1746076850, -14219288965, -3492190380, 459394712, 295555148, 15415400, -9720649, -1256010, 138600, 28329, -707, -273, 0, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^21 - 273*x^19 - 707*x^18 + 28329*x^17 + 138600*x^16 - 1256010*x^15 - 9720649*x^14 + 15415400*x^13 + 295555148*x^12 + 459394712*x^11 - 3492190380*x^10 - 14219288965*x^9 - 1746076850*x^8 + 95156654696*x^7 + 227577402612*x^6 + 180231411857*x^5 - 72622185076*x^4 - 206563651595*x^3 - 96402059663*x^2 + 11414547333*x + 12861176609)
 
gp: K = bnfinit(x^21 - 273*x^19 - 707*x^18 + 28329*x^17 + 138600*x^16 - 1256010*x^15 - 9720649*x^14 + 15415400*x^13 + 295555148*x^12 + 459394712*x^11 - 3492190380*x^10 - 14219288965*x^9 - 1746076850*x^8 + 95156654696*x^7 + 227577402612*x^6 + 180231411857*x^5 - 72622185076*x^4 - 206563651595*x^3 - 96402059663*x^2 + 11414547333*x + 12861176609, 1)
 

Normalized defining polynomial

\( x^{21} - 273 x^{19} - 707 x^{18} + 28329 x^{17} + 138600 x^{16} - 1256010 x^{15} - 9720649 x^{14} + 15415400 x^{13} + 295555148 x^{12} + 459394712 x^{11} - 3492190380 x^{10} - 14219288965 x^{9} - 1746076850 x^{8} + 95156654696 x^{7} + 227577402612 x^{6} + 180231411857 x^{5} - 72622185076 x^{4} - 206563651595 x^{3} - 96402059663 x^{2} + 11414547333 x + 12861176609 \)

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:  \(103818783062189717738091671292152377422379176428329=7^{38}\cdot 19^{14}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $240.84$
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:  $7, 19$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois and abelian over $\Q$.
Conductor:  \(931=7^{2}\cdot 19\)
Dirichlet character group:    $\lbrace$$\chi_{931}(1,·)$, $\chi_{931}(387,·)$, $\chi_{931}(134,·)$, $\chi_{931}(520,·)$, $\chi_{931}(267,·)$, $\chi_{931}(653,·)$, $\chi_{931}(400,·)$, $\chi_{931}(11,·)$, $\chi_{931}(786,·)$, $\chi_{931}(533,·)$, $\chi_{931}(919,·)$, $\chi_{931}(666,·)$, $\chi_{931}(410,·)$, $\chi_{931}(799,·)$, $\chi_{931}(144,·)$, $\chi_{931}(676,·)$, $\chi_{931}(809,·)$, $\chi_{931}(121,·)$, $\chi_{931}(543,·)$, $\chi_{931}(254,·)$, $\chi_{931}(277,·)$$\rbrace$
This is not a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $a^{15}$, $\frac{1}{79} a^{16} - \frac{34}{79} a^{15} + \frac{18}{79} a^{14} - \frac{7}{79} a^{13} + \frac{19}{79} a^{12} - \frac{4}{79} a^{11} + \frac{4}{79} a^{10} - \frac{15}{79} a^{9} - \frac{39}{79} a^{8} + \frac{21}{79} a^{7} + \frac{14}{79} a^{6} + \frac{37}{79} a^{5} - \frac{9}{79} a^{4} + \frac{35}{79} a^{3} + \frac{17}{79} a^{2} + \frac{12}{79} a - \frac{8}{79}$, $\frac{1}{79} a^{17} - \frac{32}{79} a^{15} - \frac{27}{79} a^{14} + \frac{18}{79} a^{13} + \frac{10}{79} a^{12} + \frac{26}{79} a^{11} - \frac{37}{79} a^{10} + \frac{4}{79} a^{9} + \frac{38}{79} a^{8} + \frac{17}{79} a^{7} + \frac{39}{79} a^{6} - \frac{15}{79} a^{5} - \frac{34}{79} a^{4} + \frac{22}{79} a^{3} + \frac{37}{79} a^{2} + \frac{5}{79} a - \frac{35}{79}$, $\frac{1}{100567} a^{18} + \frac{27}{100567} a^{17} + \frac{441}{100567} a^{16} - \frac{20054}{100567} a^{15} - \frac{1714}{5293} a^{14} - \frac{31097}{100567} a^{13} - \frac{7307}{100567} a^{12} + \frac{39853}{100567} a^{11} - \frac{1236}{100567} a^{10} - \frac{20221}{100567} a^{9} - \frac{21196}{100567} a^{8} + \frac{14065}{100567} a^{7} - \frac{7824}{100567} a^{6} - \frac{15407}{100567} a^{5} + \frac{49752}{100567} a^{4} - \frac{46962}{100567} a^{3} + \frac{44200}{100567} a^{2} - \frac{36094}{100567} a - \frac{30088}{100567}$, $\frac{1}{100567} a^{19} - \frac{288}{100567} a^{17} - \frac{136}{100567} a^{16} + \frac{30244}{100567} a^{15} + \frac{13097}{100567} a^{14} + \frac{6135}{100567} a^{13} + \frac{37281}{100567} a^{12} + \frac{2237}{100567} a^{11} + \frac{39884}{100567} a^{10} + \frac{47396}{100567} a^{9} + \frac{49151}{100567} a^{8} - \frac{20955}{100567} a^{7} + \frac{567}{1501} a^{6} + \frac{34194}{100567} a^{5} + \frac{32948}{100567} a^{4} + \frac{12441}{100567} a^{3} + \frac{15500}{100567} a^{2} + \frac{18979}{100567} a - \frac{45626}{100567}$, $\frac{1}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{20} - \frac{120001436932845487503212976081358737730748963844918563452798847203612926868994391}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{19} - \frac{241631600196875453834916612418059119204986515720496272680077593612149759210574340}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{18} + \frac{236382854887319064220547063190412956606415733628212711493776787839904131438807085462}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{17} - \frac{94896415076280531707492652189357156784671040759154446791508161307359784749349312863}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{16} + \frac{3265220424323050159316479962612102996581141692796099183738583635251842294214761295369}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{15} + \frac{23550408101498163067128593601632887421117864063808974915723263764864613091704371745167}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{14} - \frac{1422989744177178680948414418339582528849592703293429082029117125377344853050892734555}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{13} - \frac{22136437570277715112778873214514790089313758606721802762162678954856257116965216471311}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{12} + \frac{77510828410019691664470810542989318810626289031783546583523595462140332183112837607}{2664545195865838838473249633479796286686061665189538936864796510349507689515289332711} a^{11} + \frac{13344014324137340899354784362936575831564833089738034250394744452830990752159703397441}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{10} + \frac{3652518745857581931223654032479678777002714261546986944850232978520291067068845962711}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{9} + \frac{15837615760551688700850677904729653785028498153098456007086303903944875825507051347200}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{8} - \frac{13570419443260203770881938026911487478480719757605625217188014485200219137778954992471}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{7} - \frac{20762963596101642909996211085372963584503942376656699451330883470873307025425298198313}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{6} - \frac{23644077478015791811338270415182594622605615995554458968940917780579245405845182762410}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{5} + \frac{19271184164190112914975554637624745045624647391882108726556841942450789049910965832417}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{4} - \frac{62910492358495884676658349013348275540097802431259185065172439648849038784198677419}{640839983815834657354325861216659866418166729602547339245963717678995520263170852171} a^{3} + \frac{12094683079957741106102845627983024110159502176794659764612795535972036270610493869293}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a^{2} + \frac{10839260613217096330070162580057055822554398938012723539010118582023812449149499262229}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509} a - \frac{3017251367010048237430094762218439116413492312087031555288651440765302793720223098433}{50626358721450937930991743036116129447035171638601239800431133696640646100790497321509}$

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

Class group and class number

$C_{3}$, which has order $3$ (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:  \( 1030828564219823600 \) (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

3.3.17689.2, 7.7.13841287201.1

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 ${\href{/LocalNumberField/2.7.0.1}{7} }^{3}$ $21$ ${\href{/LocalNumberField/5.7.0.1}{7} }^{3}$ R $21$ $21$ $21$ R $21$ $21$ ${\href{/LocalNumberField/31.3.0.1}{3} }^{7}$ $21$ $21$ $21$ $21$ ${\href{/LocalNumberField/53.7.0.1}{7} }^{3}$ $21$

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
7Data not computed
$19$19.3.2.1$x^{3} + 76$$3$$1$$2$$C_3$$[\ ]_{3}$
19.3.2.1$x^{3} + 76$$3$$1$$2$$C_3$$[\ ]_{3}$
19.3.2.1$x^{3} + 76$$3$$1$$2$$C_3$$[\ ]_{3}$
19.3.2.1$x^{3} + 76$$3$$1$$2$$C_3$$[\ ]_{3}$
19.3.2.1$x^{3} + 76$$3$$1$$2$$C_3$$[\ ]_{3}$
19.3.2.1$x^{3} + 76$$3$$1$$2$$C_3$$[\ ]_{3}$
19.3.2.1$x^{3} + 76$$3$$1$$2$$C_3$$[\ ]_{3}$