number.wiki
Number

21,121

21,121 is a prime, odd.

Deficient Number Prime Squarefree

Properties

Parity
Odd
Digit count
5
Digit sum
7
Digital root
7
Palindrome
No
Divisor count
2
σ(n) — sum of divisors
21,122

Primality

21,121 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 21121
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 21,121)
1 × 21121
First multiples
21,121 · 42,242 · 63,363 · 84,484 · 105,605 · 126,726 · 147,847 · 168,968 · 190,089 · 211,210

Representations

In words
twenty-one thousand one hundred twenty-one
Ordinal
21121st
Binary
101001010000001
Octal
51201
Hexadecimal
5281

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 21,107 (gap of 14)
  • Next prime: 21,139 (gap of 18)
Unicode codepoint
U+5281
Other letter (Lo)

UTF-8 encoding: E5 8A 81 (3 bytes).

Hex color
#005281
RGB(0, 82, 129)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.129.