number.wiki
Number

261

261 is a composite number, odd, a calendar year.

Deficient Number Harshad / Niven Year

Properties

Parity
Odd
Digit count
3
Digit sum
9
Digital root
9
Palindrome
No
Divisor count
6
σ(n) — sum of divisors
390

Primality

Prime factorization: 3 2 × 29

Divisors & multiples

All divisors (6)
1 · 3 · 9 · 29 · 87 · 261
Aliquot sum (sum of proper divisors): 129
Factor pairs (a × b = 261)
1 × 261
3 × 87
9 × 29
First multiples
261 · 522 · 783 · 1,044 · 1,305 · 1,566 · 1,827 · 2,088 · 2,349 · 2,610

Representations

In words
two hundred sixty-one
Ordinal
261st
Roman numeral
CCLXI
Binary
100000101
Octal
405
Hexadecimal
105

Also seen as

Unicode codepoint
ą
U+0105
Lowercase letter (Ll)

UTF-8 encoding: C4 85 (2 bytes).

Hex color
#000105
RGB(0, 1, 5)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.1.5.