number.wiki
Number

641

641 is a prime, odd, a calendar year.

Deficient Number Prime Sexy Prime Squarefree Twin Prime Year

Properties

Parity
Odd
Digit count
3
Digit sum
11
Digital root
2
Palindrome
No
Divisor count
2
σ(n) — sum of divisors
642

Primality

641 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 641
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 641)
1 × 641
First multiples
641 · 1,282 · 1,923 · 2,564 · 3,205 · 3,846 · 4,487 · 5,128 · 5,769 · 6,410

Representations

In words
six hundred forty-one
Ordinal
641st
Roman numeral
DCXLI
Binary
1010000001
Octal
1201
Hexadecimal
281

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 631 (gap of 10)
  • Next prime: 643 (gap of 2)

Pair status: twin with 643.

Unicode codepoint
ʁ
U+0281
Lowercase letter (Ll)

UTF-8 encoding: CA 81 (2 bytes).

Hex color
#000281
RGB(0, 2, 129)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.2.129.