number.wiki
Number

21,019

21,019 is a prime, odd.

Cousin Prime Deficient Number Prime Sexy Prime Squarefree Twin Prime

Properties

Parity
Odd
Digit count
5
Digit sum
13
Digital root
4
Palindrome
No
Divisor count
2
σ(n) — sum of divisors
21,020

Primality

21,019 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 21019
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 21,019)
1 × 21019
First multiples
21,019 · 42,038 · 63,057 · 84,076 · 105,095 · 126,114 · 147,133 · 168,152 · 189,171 · 210,190

Representations

In words
twenty-one thousand nineteen
Ordinal
21019th
Binary
101001000011011
Octal
51033
Hexadecimal
521B

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 21,017 (gap of 2)
  • Next prime: 21,023 (gap of 4)

Pair status: twin with 21017, cousin with 21023.

Unicode codepoint
U+521B
Other letter (Lo)

UTF-8 encoding: E5 88 9B (3 bytes).

Hex color
#00521B
RGB(0, 82, 27)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.27.