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Number

21,191

21,191 is a prime, odd.

Cousin Prime Deficient Number Prime Squarefree Twin Prime

Properties

Parity
Odd
Digit count
5
Digit sum
14
Digital root
5
Palindrome
No
Divisor count
2
σ(n) — sum of divisors
21,192

Primality

21,191 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 21191
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 21,191)
1 × 21191
First multiples
21,191 · 42,382 · 63,573 · 84,764 · 105,955 · 127,146 · 148,337 · 169,528 · 190,719 · 211,910

Representations

In words
twenty-one thousand one hundred ninety-one
Ordinal
21191st
Binary
101001011000111
Octal
51307
Hexadecimal
52C7

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 21,187 (gap of 4)
  • Next prime: 21,193 (gap of 2)

Pair status: twin with 21193, cousin with 21187.

Unicode codepoint
U+52C7
Other letter (Lo)

UTF-8 encoding: E5 8B 87 (3 bytes).

Hex color
#0052C7
RGB(0, 82, 199)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.199.