4 21 polytope
SEMIREGULAR UNIFORM 8-POLYTOPE
Gosset 4 21 polytope; Rectified 4 21 polytope; Birectified 4 21 polytope; Trirectified 4 21 polytope; Borfy; Birectified dischiliahectohexaconta-myriaheptachiliadiacosioctaconta-zetton; Torfy; Trirectified dischiliahectohexaconta-myriaheptachiliadiacosioctaconta-zetton; Rectifed 4 21
In 8-dimensional geometry, the 421 is a semiregular uniform 8-polytope, constructed within the symmetry of the E8 group. It was discovered by Thorold Gosset, published in his 1900 paper.