number.wiki
Number

72

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

Abundant Number Achilles Number Harshad / Niven Powerful Number Pronic / Oblong Year

Properties

Parity
Even
Digit count
2
Digit sum
9
Digital root
9
Palindrome
No
Divisor count
12
σ(n) — sum of divisors
195

Primality

Prime factorization: 2 3 × 3 2

Divisors & multiples

All divisors (12)
1 · 2 · 3 · 4 · 6 · 8 · 9 · 12 · 18 · 24 · 36 · 72
Aliquot sum (sum of proper divisors): 123
Factor pairs (a × b = 72)
1 × 72
2 × 36
3 × 24
4 × 18
6 × 12
8 × 9
First multiples
72 · 144 · 216 · 288 · 360 · 432 · 504 · 576 · 648 · 720

Representations

In words
seventy-two
Ordinal
72nd
Roman numeral
LXXII
Binary
1001000
Octal
110
Hexadecimal
48

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 72, here are decompositions:

  • 5 + 67 = 72
  • 11 + 61 = 72
  • 13 + 59 = 72
  • 19 + 53 = 72
  • 29 + 43 = 72
  • 31 + 41 = 72
ASCII character

As an ASCII codepoint, 72 is H. Printable ASCII character H.

Hex color
#000048
RGB(0, 0, 72)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.72.