Properties

Label 21.21.9945786510...2561.1
Degree $21$
Signature $[21, 0]$
Discriminant $13^{14}\cdot 43^{18}$
Root discriminant $138.91$
Ramified primes $13, 43$
Class number $1$ (GRH)
Class group Trivial (GRH)
Galois group $C_{21}$ (as 21T1)

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magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![-23557, -61380, 1434512, -2993437, -3647782, 10795899, 2345155, -12783623, -739098, 7477031, 392282, -2399473, -196925, 429292, 43542, -43774, -4502, 2534, 218, -78, -4, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^21 - 4*x^20 - 78*x^19 + 218*x^18 + 2534*x^17 - 4502*x^16 - 43774*x^15 + 43542*x^14 + 429292*x^13 - 196925*x^12 - 2399473*x^11 + 392282*x^10 + 7477031*x^9 - 739098*x^8 - 12783623*x^7 + 2345155*x^6 + 10795899*x^5 - 3647782*x^4 - 2993437*x^3 + 1434512*x^2 - 61380*x - 23557)
 
gp: K = bnfinit(x^21 - 4*x^20 - 78*x^19 + 218*x^18 + 2534*x^17 - 4502*x^16 - 43774*x^15 + 43542*x^14 + 429292*x^13 - 196925*x^12 - 2399473*x^11 + 392282*x^10 + 7477031*x^9 - 739098*x^8 - 12783623*x^7 + 2345155*x^6 + 10795899*x^5 - 3647782*x^4 - 2993437*x^3 + 1434512*x^2 - 61380*x - 23557, 1)
 

Normalized defining polynomial

\( x^{21} - 4 x^{20} - 78 x^{19} + 218 x^{18} + 2534 x^{17} - 4502 x^{16} - 43774 x^{15} + 43542 x^{14} + 429292 x^{13} - 196925 x^{12} - 2399473 x^{11} + 392282 x^{10} + 7477031 x^{9} - 739098 x^{8} - 12783623 x^{7} + 2345155 x^{6} + 10795899 x^{5} - 3647782 x^{4} - 2993437 x^{3} + 1434512 x^{2} - 61380 x - 23557 \)

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:  \(994578651055668861859035058398460943925772561=13^{14}\cdot 43^{18}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $138.91$
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:  $13, 43$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is Galois and abelian over $\Q$.
Conductor:  \(559=13\cdot 43\)
Dirichlet character group:    $\lbrace$$\chi_{559}(256,·)$, $\chi_{559}(1,·)$, $\chi_{559}(451,·)$, $\chi_{559}(133,·)$, $\chi_{559}(391,·)$, $\chi_{559}(87,·)$, $\chi_{559}(269,·)$, $\chi_{559}(16,·)$, $\chi_{559}(274,·)$, $\chi_{559}(471,·)$, $\chi_{559}(477,·)$, $\chi_{559}(35,·)$, $\chi_{559}(484,·)$, $\chi_{559}(360,·)$, $\chi_{559}(170,·)$, $\chi_{559}(107,·)$, $\chi_{559}(365,·)$, $\chi_{559}(302,·)$, $\chi_{559}(183,·)$, $\chi_{559}(250,·)$, $\chi_{559}(508,·)$$\rbrace$
This is not a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $\frac{1}{7} a^{15} + \frac{1}{7} a^{14} + \frac{3}{7} a^{13} - \frac{3}{7} a^{11} + \frac{1}{7} a^{10} - \frac{1}{7} a^{8} - \frac{3}{7} a^{7} - \frac{1}{7} a^{6} + \frac{2}{7} a^{5} + \frac{2}{7} a^{4} + \frac{3}{7} a^{3} - \frac{2}{7} a^{2} + \frac{1}{7} a + \frac{2}{7}$, $\frac{1}{7} a^{16} + \frac{2}{7} a^{14} - \frac{3}{7} a^{13} - \frac{3}{7} a^{12} - \frac{3}{7} a^{11} - \frac{1}{7} a^{10} - \frac{1}{7} a^{9} - \frac{2}{7} a^{8} + \frac{2}{7} a^{7} + \frac{3}{7} a^{6} + \frac{1}{7} a^{4} + \frac{2}{7} a^{3} + \frac{3}{7} a^{2} + \frac{1}{7} a - \frac{2}{7}$, $\frac{1}{7} a^{17} + \frac{2}{7} a^{14} - \frac{2}{7} a^{13} - \frac{3}{7} a^{12} - \frac{2}{7} a^{11} - \frac{3}{7} a^{10} - \frac{2}{7} a^{9} - \frac{3}{7} a^{8} + \frac{2}{7} a^{7} + \frac{2}{7} a^{6} - \frac{3}{7} a^{5} - \frac{2}{7} a^{4} - \frac{3}{7} a^{3} - \frac{2}{7} a^{2} + \frac{3}{7} a + \frac{3}{7}$, $\frac{1}{7} a^{18} + \frac{3}{7} a^{14} - \frac{2}{7} a^{13} - \frac{2}{7} a^{12} + \frac{3}{7} a^{11} + \frac{3}{7} a^{10} - \frac{3}{7} a^{9} - \frac{3}{7} a^{8} + \frac{1}{7} a^{7} - \frac{1}{7} a^{6} + \frac{1}{7} a^{5} - \frac{1}{7} a^{3} + \frac{1}{7} a + \frac{3}{7}$, $\frac{1}{2359} a^{19} + \frac{16}{337} a^{18} - \frac{5}{337} a^{17} + \frac{25}{2359} a^{16} - \frac{8}{2359} a^{15} - \frac{243}{2359} a^{14} + \frac{289}{2359} a^{13} - \frac{1080}{2359} a^{12} + \frac{836}{2359} a^{11} + \frac{234}{2359} a^{10} + \frac{34}{337} a^{9} + \frac{900}{2359} a^{8} - \frac{1066}{2359} a^{7} + \frac{3}{7} a^{6} + \frac{923}{2359} a^{5} + \frac{548}{2359} a^{4} + \frac{94}{2359} a^{3} - \frac{22}{337} a^{2} + \frac{843}{2359} a - \frac{933}{2359}$, $\frac{1}{41741673481512110235679620268566346291836806648449} a^{20} - \frac{7550672483780801602279273544606106534554230295}{41741673481512110235679620268566346291836806648449} a^{19} + \frac{1313718214338338584507640931276895033914204439261}{41741673481512110235679620268566346291836806648449} a^{18} - \frac{133051298552079538996011222550667277868237382010}{5963096211644587176525660038366620898833829521207} a^{17} + \frac{1956137197694311139794471493194499806386813495877}{41741673481512110235679620268566346291836806648449} a^{16} + \frac{1892077354486054544633809881413419899495069549920}{41741673481512110235679620268566346291836806648449} a^{15} + \frac{19944203360314900828860643418970818627537620322103}{41741673481512110235679620268566346291836806648449} a^{14} - \frac{18392279456543195047784370972653814335916086035072}{41741673481512110235679620268566346291836806648449} a^{13} + \frac{16107306871636512582729270250562114497661304738642}{41741673481512110235679620268566346291836806648449} a^{12} + \frac{6745760378278429848121665956366622290195228637022}{41741673481512110235679620268566346291836806648449} a^{11} + \frac{9755361351018878199756896325028546584222193785032}{41741673481512110235679620268566346291836806648449} a^{10} - \frac{1086866470352955370341122419898502442803203610203}{41741673481512110235679620268566346291836806648449} a^{9} - \frac{12056834858825879018746145261892885997398431866429}{41741673481512110235679620268566346291836806648449} a^{8} + \frac{17813483751846560484458057578490419104723112548510}{41741673481512110235679620268566346291836806648449} a^{7} - \frac{10958030567056764914537824140834468118180883202731}{41741673481512110235679620268566346291836806648449} a^{6} + \frac{126097867424484817758777819315970040066970105619}{5963096211644587176525660038366620898833829521207} a^{5} - \frac{9170786333793420006291218231149569216696841243555}{41741673481512110235679620268566346291836806648449} a^{4} + \frac{14162204966064165575094833758982841562141016115318}{41741673481512110235679620268566346291836806648449} a^{3} + \frac{6408340020404012314679352857397741300560335169913}{41741673481512110235679620268566346291836806648449} a^{2} - \frac{4819316964311830926943079480551337240971168461768}{41741673481512110235679620268566346291836806648449} a + \frac{15965434241713217641589771132796539108742861111928}{41741673481512110235679620268566346291836806648449}$

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:  \( 4188365147703962.5 \) (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

3.3.169.1, 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 $21$ $21$ ${\href{/LocalNumberField/5.7.0.1}{7} }^{3}$ ${\href{/LocalNumberField/7.3.0.1}{3} }^{7}$ $21$ R $21$ $21$ $21$ $21$ ${\href{/LocalNumberField/31.7.0.1}{7} }^{3}$ ${\href{/LocalNumberField/37.3.0.1}{3} }^{7}$ $21$ R ${\href{/LocalNumberField/47.7.0.1}{7} }^{3}$ ${\href{/LocalNumberField/53.7.0.1}{7} }^{3}$ $21$

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
13Data not computed
43Data not computed