As we ease into 2021, here are 21 fun facts related to the number 21. 1 21 in Roman numerals is XXI. 2 21 is a triangle number – it is the sum of the first six whole numbers (1+2+3+4+5+6=21).

These are some of the design exhibitions, openings, interiors and creatives that shaped 2021, from an exploration of the boundaries of textiles by Hella Jongerius to an overview of Charlotte ...