Number
648
648 is a composite number, even, a calendar year.
Properties
- Parity
- Even
- Digit count
- 3
- Digit sum
- 18
- Digital root
- 9
- Palindrome
- No
- Divisor count
- 20
- σ(n) — sum of divisors
- 1,815
Primality
Prime factorization: 2 3 × 3 4
Divisors & multiples
All divisors (20)
Aliquot sum (sum of proper divisors):
1,167
Factor pairs (a × b = 648)
Representations
- In words
- six hundred forty-eight
- Ordinal
- 648th
- Roman numeral
- DCXLVIII
- Binary
- 1010001000
- Octal
- 1210
- Hexadecimal
- 288
Also seen as
Goldbach decomposition
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 648, here are decompositions:
- 5 + 643 = 648
- 7 + 641 = 648
- 17 + 631 = 648
- 29 + 619 = 648
- 31 + 617 = 648
- 41 + 607 = 648
- 47 + 601 = 648
- 61 + 587 = 648
Showing the first eight; more decompositions exist.
Unicode codepoint
ʈ
U+0288
Lowercase letter (Ll)
UTF-8 encoding: CA 88 (2 bytes).
Hex color
#000288
RGB(0, 2, 136)
IPv4 address
As an unsigned 32-bit integer, this is the IPv4 address 0.0.2.136.