Number

1,800

1,800 is a composite number, even, a calendar year.

Abundant Number Achilles Number Harshad / Niven Powerful Number Year

Properties

Parity: Even
Digit count: 4
Digit sum: 9
Digital root: 9
Palindrome: No
Divisor count: 36
σ(n) — sum of divisors: 6,045

Primality

Prime factorization: 2 ³ × 3 ² × 5 ²

Divisors & multiples

All divisors (36)

1 · 2 · 3 · 4 · 5 · 6 · 8 · 9 · 10 · 12 · 15 · 18 · 20 · 24 · 25 · 30 · 36 · 40 · 45 · 50 · 60 · 72 · 75 · 90 · 100 · 120 · 150 · 180 · 200 · 225 · 300 · 360 · 450 · 600 · 900 · 1800

Aliquot sum (sum of proper divisors): 4,245

Factor pairs (a × b = 1,800)

1 × 1800

2 × 900

3 × 600

4 × 450

5 × 360

6 × 300

8 × 225

9 × 200

10 × 180

12 × 150

15 × 120

18 × 100

20 × 90

24 × 75

25 × 72

30 × 60

36 × 50

40 × 45

First multiples

1,800 · 3,600 · 5,400 · 7,200 · 9,000 · 10,800 · 12,600 · 14,400 · 16,200 · 18,000

Representations

In words: one thousand eight hundred
Ordinal: 1800th
Roman numeral: MDCCC
Binary: 11100001000
Octal: 3410
Hexadecimal: 708

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1800, here are decompositions:

11 + 1789 = 1800
13 + 1787 = 1800
17 + 1783 = 1800
23 + 1777 = 1800
41 + 1759 = 1800
47 + 1753 = 1800
53 + 1747 = 1800
59 + 1741 = 1800

Showing the first eight; more decompositions exist.

Unicode codepoint

U+0708

Other punctuation (Po)

UTF-8 encoding: DC 88 (2 bytes).

Lookup U+0708 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000708

RGB(0, 7, 8)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.7.8.