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Properties

Label 21.21.1890842602...3929.1
Degree $21$
Signature $[21, 0]$
Discriminant $29^{18}\cdot 9478633^{2}$
Root discriminant $82.78$
Ramified primes $29, 9478633$
Class number $1$ (GRH)
Class group Trivial (GRH)
Galois group 21T61

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Show commands for: Magma / SageMath / Pari/GP

magma: R<x> := PolynomialRing(Rationals()); K<a> := NumberField(R![1, -15, 78, -104, -496, 1982, -1363, -4985, 9880, -928, -12723, 9642, 4308, -7671, 1246, 2061, -894, -145, 142, -12, -6, 1]);
 
sage: x = polygen(QQ); K.<a> = NumberField(x^21 - 6*x^20 - 12*x^19 + 142*x^18 - 145*x^17 - 894*x^16 + 2061*x^15 + 1246*x^14 - 7671*x^13 + 4308*x^12 + 9642*x^11 - 12723*x^10 - 928*x^9 + 9880*x^8 - 4985*x^7 - 1363*x^6 + 1982*x^5 - 496*x^4 - 104*x^3 + 78*x^2 - 15*x + 1)
 
gp: K = bnfinit(x^21 - 6*x^20 - 12*x^19 + 142*x^18 - 145*x^17 - 894*x^16 + 2061*x^15 + 1246*x^14 - 7671*x^13 + 4308*x^12 + 9642*x^11 - 12723*x^10 - 928*x^9 + 9880*x^8 - 4985*x^7 - 1363*x^6 + 1982*x^5 - 496*x^4 - 104*x^3 + 78*x^2 - 15*x + 1, 1)
 

Normalized defining polynomial

\( x^{21} - 6 x^{20} - 12 x^{19} + 142 x^{18} - 145 x^{17} - 894 x^{16} + 2061 x^{15} + 1246 x^{14} - 7671 x^{13} + 4308 x^{12} + 9642 x^{11} - 12723 x^{10} - 928 x^{9} + 9880 x^{8} - 4985 x^{7} - 1363 x^{6} + 1982 x^{5} - 496 x^{4} - 104 x^{3} + 78 x^{2} - 15 x + 1 \)

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:  \(18908426022848469258131981954191571483929=29^{18}\cdot 9478633^{2}\)
magma: Discriminant(Integers(K));
 
sage: K.disc()
 
gp: K.disc
 
Root discriminant:  $82.78$
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:  $29, 9478633$
magma: PrimeDivisors(Discriminant(Integers(K)));
 
sage: K.disc().support()
 
gp: factor(abs(K.disc))[,1]~
 
This field is not Galois over $\Q$.
This is not a CM field.

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

$1$, $a$, $a^{2}$, $a^{3}$, $a^{4}$, $a^{5}$, $a^{6}$, $a^{7}$, $a^{8}$, $a^{9}$, $a^{10}$, $a^{11}$, $a^{12}$, $a^{13}$, $a^{14}$, $a^{15}$, $a^{16}$, $a^{17}$, $\frac{1}{17} a^{18} - \frac{8}{17} a^{17} - \frac{8}{17} a^{16} - \frac{2}{17} a^{15} - \frac{3}{17} a^{14} - \frac{6}{17} a^{13} + \frac{3}{17} a^{12} + \frac{6}{17} a^{11} + \frac{5}{17} a^{10} + \frac{7}{17} a^{9} + \frac{8}{17} a^{8} + \frac{7}{17} a^{7} - \frac{8}{17} a^{6} - \frac{5}{17} a^{5} - \frac{7}{17} a^{4} - \frac{6}{17} a^{3} - \frac{8}{17} a^{2} + \frac{7}{17} a + \frac{1}{17}$, $\frac{1}{17} a^{19} - \frac{4}{17} a^{17} + \frac{2}{17} a^{16} - \frac{2}{17} a^{15} + \frac{4}{17} a^{14} + \frac{6}{17} a^{13} - \frac{4}{17} a^{12} + \frac{2}{17} a^{11} - \frac{4}{17} a^{10} - \frac{4}{17} a^{9} + \frac{3}{17} a^{8} - \frac{3}{17} a^{7} - \frac{1}{17} a^{6} + \frac{4}{17} a^{5} + \frac{6}{17} a^{4} - \frac{5}{17} a^{3} - \frac{6}{17} a^{2} + \frac{6}{17} a + \frac{8}{17}$, $\frac{1}{17} a^{20} + \frac{4}{17} a^{17} - \frac{4}{17} a^{15} - \frac{6}{17} a^{14} + \frac{6}{17} a^{13} - \frac{3}{17} a^{12} + \frac{3}{17} a^{11} - \frac{1}{17} a^{10} - \frac{3}{17} a^{9} - \frac{5}{17} a^{8} - \frac{7}{17} a^{7} + \frac{6}{17} a^{6} + \frac{3}{17} a^{5} + \frac{1}{17} a^{4} + \frac{4}{17} a^{3} + \frac{8}{17} a^{2} + \frac{2}{17} a + \frac{4}{17}$

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:  \( 20651297489000 \) (assuming GRH)
magma: Regulator(K);
 
sage: K.regulator()
 
gp: K.reg
 

Galois group

21T61:

magma: GaloisGroup(K);
 
sage: K.galois_group(type='pari')
 
gp: polgalois(K.pol)
 
A solvable group of order 15309
The 333 conjugacy class representatives for t21n61 are not computed
Character table for t21n61 is not computed

Intermediate fields

7.7.594823321.1

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

Sibling fields

Degree 21 siblings: data not computed

Frobenius cycle types

$p$ 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59
Cycle type $21$ $21$ $21$ $21$ ${\href{/LocalNumberField/11.7.0.1}{7} }^{3}$ $21$ ${\href{/LocalNumberField/17.3.0.1}{3} }^{7}$ $21$ $21$ R $21$ $21$ ${\href{/LocalNumberField/41.3.0.1}{3} }^{4}{,}\,{\href{/LocalNumberField/41.1.0.1}{1} }^{9}$ ${\href{/LocalNumberField/43.7.0.1}{7} }^{3}$ $21$ $21$ ${\href{/LocalNumberField/59.3.0.1}{3} }^{6}{,}\,{\href{/LocalNumberField/59.1.0.1}{1} }^{3}$

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
29Data not computed
9478633Data not computed