\\ Pari/GP code for working with number field 20.20.17687695508088196514062500000000000000000000.1.
\\ Some of these functions may take a long time to execute (this depends on the field).


\\ Define the number field: 
K = bnfinit(y^20 - 160*y^18 + 10790*y^16 - 372*y^15 - 400000*y^14 + 37080*y^13 + 8908075*y^12 - 1405800*y^11 - 122060112*y^10 + 25437000*y^9 + 1009834870*y^8 - 221247000*y^7 - 4729220200*y^6 + 784838688*y^5 + 10914530225*y^4 - 681612780*y^3 - 8806862800*y^2 + 1007795640*y + 916095316, 1)

\\ Defining polynomial: 
K.pol

\\ Degree over Q: 
poldegree(K.pol)

\\ Signature: 
K.sign

\\ Discriminant: 
K.disc

\\ Ramified primes: 
factor(abs(K.disc))[,1]~

\\ Integral basis: 
K.zk

\\ Class group: 
K.clgp

\\ Narrow class group: 
bnfnarrow(K)

\\ Unit rank: 
K.fu

\\ Generator for roots of unity: 
K.tu[2]

\\ Fundamental units: 
K.fu

\\ Regulator: 
K.reg

\\ Analytic class number formula: 
\\ self-contained Pari/GP code snippet to compute the analytic class number formula
K = bnfinit(x^20 - 160*x^18 + 10790*x^16 - 372*x^15 - 400000*x^14 + 37080*x^13 + 8908075*x^12 - 1405800*x^11 - 122060112*x^10 + 25437000*x^9 + 1009834870*x^8 - 221247000*x^7 - 4729220200*x^6 + 784838688*x^5 + 10914530225*x^4 - 681612780*x^3 - 8806862800*x^2 + 1007795640*x + 916095316, 1);
[polcoeff (lfunrootres (lfuncreate (K))[1][1][2], -1), 2^K.r1 * (2*Pi)^K.r2 * K.reg * K.no / (K.tu[1] * sqrt (abs (K.disc)))]

\\ Intermediate fields: 
L = nfsubfields(K); L[2..length(L)]

\\ Galois group: 
polgalois(K.pol)

\\ Frobenius cycle types: 
\\ to obtain a list of [e_i,f_i] for the factorization of the ideal pO_K for p=7 in Pari:
p = 7; pfac = idealprimedec(K, p); vector(length(pfac), j, [pfac[j][3], pfac[j][4]])