Numberblocks Wiki

Twenty-One, or 21, is a character that is made of 21 blocks. She is voiced by Emma Tate.


Twenty-One originally appeared as literally "Twenty + One". Most fans argued that it wasn't her actual design, which proved to be correct. Twenty-One wears camping luggage and a green Tyrolean hat with three rainbow coloured "feathers", because she is 3x7. She wears a stepmask because she is the 6th step squad, and two boots, apricot and red. She can also be seen holding a walking stick.

Episode Appearances


Number Explorer Twenty-One is the smallest number that first appeared as a compound. She is usually seen as 3x7 or a staircase shape with six steps.

2D (52/88,983,512,783)

Figured-Out (43)
Compound Only (9)



Twenty and One

  • 21 was the first Numberblock to have more than two eyes and one mouth.
    • They were also the first Numberblock to have two faces.
  • The fact that the 21 in I Can Count to Twenty is just 20 and 1 conjoined reflects how the Alphablocks form digraphs and trigraphs in their show (For example: Q conjoins herself with U to form the digraph "qu"; H, with C, S, and T, form "ch", "sh", and "th" respectively; I, G, and H form the trigraph "igh"; two O's conjoin with each other to form "oo", etc.).

Twenty-One's own character

  • Twenty-One is the first Numberblock to exceed Twenty.
  • She is the second character to have a permanent step squad mask. The first being Fifteen.
    • One, Three, Six and Ten had step squad masks in Step Squads, but they weren't permanent.
  • It's possible that Twenty-One had an early design concept before her final one. Her appearance as sketched the storyboard of We're Going On A Square Hunt (viewable in this compilation) looks quite different. In it, she has no hat or backpack, her face is on the bottom of her blocks, and she seems to have hair similar to Seven's.