Number
21,001
21,001 is a prime, odd.
Properties
- Parity
- Odd
- Digit count
- 5
- Digit sum
- 4
- Digital root
- 4
- Palindrome
- No
- Divisor count
- 2
- σ(n) — sum of divisors
- 21,002
Primality
21,001 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Aliquot sum (sum of proper divisors):
1
First multiples
Representations
- In words
- twenty-one thousand one
- Ordinal
- 21001st
- Binary
- 101001000001001
- Octal
- 51011
- Hexadecimal
- 5209
Also seen as
Unicode codepoint
刉
U+5209
Other letter (Lo)
UTF-8 encoding: E5 88 89 (3 bytes).
Hex color
#005209
RGB(0, 82, 9)
IPv4 address
As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.9.