number.wiki
Number

728

728 is a composite number, even, a calendar year.

Abundant Number Smith Number Year

Properties

Parity
Even
Digit count
3
Digit sum
17
Digital root
8
Palindrome
No
Divisor count
16
σ(n) — sum of divisors
1,680

Primality

Prime factorization: 2 3 × 7 × 13

Divisors & multiples

All divisors (16)
1 · 2 · 4 · 7 · 8 · 13 · 14 · 26 · 28 · 52 · 56 · 91 · 104 · 182 · 364 · 728
Aliquot sum (sum of proper divisors): 952
Factor pairs (a × b = 728)
1 × 728
2 × 364
4 × 182
7 × 104
8 × 91
13 × 56
14 × 52
26 × 28
First multiples
728 · 1,456 · 2,184 · 2,912 · 3,640 · 4,368 · 5,096 · 5,824 · 6,552 · 7,280

Representations

In words
seven hundred twenty-eight
Ordinal
728th
Roman numeral
DCCXXVIII
Binary
1011011000
Octal
1330
Hexadecimal
2D8

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 728, here are decompositions:

  • 19 + 709 = 728
  • 37 + 691 = 728
  • 67 + 661 = 728
  • 97 + 631 = 728
  • 109 + 619 = 728
  • 127 + 601 = 728
  • 151 + 577 = 728
  • 157 + 571 = 728

Showing the first eight; more decompositions exist.

Unicode codepoint
˘
U+02D8
Modifier symbol (Sk)

UTF-8 encoding: CB 98 (2 bytes).

Lookup U+02D8 on Compart ↗ Lookup on FileFormat.Info ↗
Hex color
#0002D8
RGB(0, 2, 216)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.2.216.