number.wiki
Number

4,021

4,021 is a prime, odd.

Deficient Number Prime Sexy Prime Squarefree Twin Prime

Properties

Parity
Odd
Digit count
4
Digit sum
7
Digital root
7
Palindrome
No
Divisor count
2
σ(n) — sum of divisors
4,022

Primality

4,021 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 4021
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 4,021)
1 × 4021
First multiples
4,021 · 8,042 · 12,063 · 16,084 · 20,105 · 24,126 · 28,147 · 32,168 · 36,189 · 40,210

Representations

In words
four thousand twenty-one
Ordinal
4021st
Binary
111110110101
Octal
7665
Hexadecimal
FB5

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 4,019 (gap of 2)
  • Next prime: 4,027 (gap of 6)

Pair status: twin with 4019, sexy with 4027.

Unicode codepoint
U+0FB5
Non-spacing mark (Mn)

UTF-8 encoding: E0 BE B5 (3 bytes).

Hex color
#000FB5
RGB(0, 15, 181)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.15.181.