number.wiki
Number

21,397

21,397 is a prime, odd.

Cousin Prime Deficient Number Prime Sexy Prime Squarefree

Properties

Parity
Odd
Digit count
5
Digit sum
22
Digital root
4
Palindrome
No
Divisor count
2
σ(n) — sum of divisors
21,398

Primality

21,397 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 21397
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 21,397)
1 × 21397
First multiples
21,397 · 42,794 · 64,191 · 85,588 · 106,985 · 128,382 · 149,779 · 171,176 · 192,573 · 213,970

Representations

In words
twenty-one thousand three hundred ninety-seven
Ordinal
21397th
Binary
101001110010101
Octal
51625
Hexadecimal
5395

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 21,391 (gap of 6)
  • Next prime: 21,401 (gap of 4)

Pair status: cousin with 21401, sexy with 21391.

Unicode codepoint
U+5395
Other letter (Lo)

UTF-8 encoding: E5 8E 95 (3 bytes).

Hex color
#005395
RGB(0, 83, 149)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.83.149.