Comments from the [prime page for (twenty one)](twenty - prime details | uchisen - Learn Japanese Visually one) - Join the discussion by posting a comment!
廿 - twenty one
Remember this by some simple math: two 十 (Ten)s and a 一 (One) make twenty one.This prime comes from a kanji with the same meaning, but since it’s not a part of the Jouyou kanji we’ll just remember this as a prime.
Grade: 3
Strokes: 4