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Number

1,640

1,640 is a composite number, even, a calendar year.

Abundant Number Pronic / Oblong Year

Properties

Parity
Even
Digit count
4
Digit sum
11
Digital root
2
Palindrome
No
Divisor count
16
σ(n) — sum of divisors
3,780

Primality

Prime factorization: 2 3 × 5 × 41

Divisors & multiples

All divisors (16)
1 · 2 · 4 · 5 · 8 · 10 · 20 · 40 · 41 · 82 · 164 · 205 · 328 · 410 · 820 · 1640
Aliquot sum (sum of proper divisors): 2,140
Factor pairs (a × b = 1,640)
1 × 1640
2 × 820
4 × 410
5 × 328
8 × 205
10 × 164
20 × 82
40 × 41
First multiples
1,640 · 3,280 · 4,920 · 6,560 · 8,200 · 9,840 · 11,480 · 13,120 · 14,760 · 16,400

Representations

In words
one thousand six hundred forty
Ordinal
1640th
Roman numeral
MDCXL
Binary
11001101000
Octal
3150
Hexadecimal
668

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1640, here are decompositions:

  • 3 + 1637 = 1640
  • 13 + 1627 = 1640
  • 19 + 1621 = 1640
  • 31 + 1609 = 1640
  • 43 + 1597 = 1640
  • 61 + 1579 = 1640
  • 73 + 1567 = 1640
  • 97 + 1543 = 1640

Showing the first eight; more decompositions exist.

Unicode codepoint
٨
U+0668
Decimal digit (Nd)

UTF-8 encoding: D9 A8 (2 bytes).

Lookup U+0668 on Compart ↗ Lookup on FileFormat.Info ↗
Hex color
#000668
RGB(0, 6, 104)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.6.104.