HistorianBook.com project of numbers.

21 information.

21
Change language21 in English words
twenty-one
XXI
odd
Square root
4.5825756949558
Binary number
10101
21 in Fibonacci Sequence
Yes
This number consist from
2 digits
Sum of 2 digits (2+1)
3
Composite number (opposite to prime number).
21 on wikipedia Google 21 #21 on instagram #21 on twitter Reverse 21 Shuffle 21
I have a thing with 21. Almost every place I've lived since I moved from my parents' house has had a 21 in the address. Dorm 1121, 1st apt 921, 2nd apt zip ended in ***21, first house 3721, second house 521.
Visitor #1
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