Number
555
- Positive
- Odd
- Composite
- 3 digits
555 is an odd 3-digit integer and a composite number. It has 8 divisors and a digital root of 6.
Number properties
ParityOddnot divisible by 2
SignPositive
PrimalityComposite
Absolute value555
Digit count3
Digit sum15
Digital root6repeated digit sum
PalindromicYesreads the same backwards
Happy numberNosquared-digit sums reach 1
Harshad numberYesdivisible by its own digit sum
Factors & divisors
Prime factorisation3 × 5 × 37
Distinct prime factors33, 5, 37
Number of divisors8
Sum of divisors σ(n)912
Aliquot sum357sum of the proper divisors
ClassificationDeficientthe aliquot sum is less than the number
Euler's totient φ(n)288integers below n that share no factor with it
SquarefreeYesno repeated prime factor
All divisors1, 3, 5, 15, 37, 111, 185, 5558 in total
Arithmetic
Representations
Decimal555
Binary100010101110 bits
Octal1053
Hexadecimal22B
Base 36FF
Roman numeralDLV
In wordsfive hundred and fifty-five
Ordinalfive hundred and fifty-fifth
Scientific notation5.55 × 10^2
Engineering notation555
Nearest landmarks
Powers & multiples
555 to the power 2308,025
555 to the power 3170,953,875
555 to the power 494,879,400,625
555 to the power 552,658,067,346,875
First ten multiples555, 1,110, 1,665, 2,220, 2,775, 3,330, 3,885, 4,440, 4,995, 5,550
Powers of twoBetween 2^9 (512) and 2^10 (1,024)
Divisibility tests
Divisible by 2No, remainder 1
Divisible by 3Yes
Divisible by 4No, remainder 3
Divisible by 5Yes
Divisible by 6No, remainder 3
Divisible by 7No, remainder 2
Divisible by 8No, remainder 3
Divisible by 9No, remainder 6
Divisible by 10No, remainder 5
Divisible by 11No, remainder 5
Divisible by 12No, remainder 3
Divisible by 100No, remainder 55
Collatz (3n + 1) trajectory
Steps to reach 130the total stopping time
Reaches 1Yesthe Collatz conjecture says every positive integer does, but it is unproven
First steps555 → 1,666 → 833 → 2,500 → 1,250 → 625 → 1,876 → 938 → 469 → 1,408 → …
Last steps… → 5 → 16 → 8 → 4 → 2 → 1
As a percentage & fraction
As a percentage55,500%
555% as a decimal5.55
555% of 100555
555% of 1,0005,550
As a fraction of 100555/100
Read another way
Keep nerding
Every link below is a page Nerdulator can generate from what it already knows about this value.
Derived from 555
Other readings
Also reads as
#555555 (colour)
- #555555
- Grey
- Dark
- Nearest: Dim grey
#555555 is a grey with RGB values 85, 85, 85 and HSL 0°, 0%, 33%. It is a dark colour, so white text on it reaches 7.5:1 contrast (AAA for normal text). The nearest named colour is Dim grey.
Colour values
#555555#555555
HEX#555555
HEX (short)#555
RGBrgb(85, 85, 85)
RGB (0–1)0.3333, 0.3333, 0.3333
RGB percentages33.3%, 33.3%, 33.3%
HSLhsl(0, 0%, 33.3%)
HSV / HSBhsv(0, 0%, 33.3%)
CMYK0%, 0%, 0%, 66.7%≈naive device-independent conversion; real print needs an ICC profile
24-bit integer5,592,405
CSS custom property--colour: #555555;
Brightness & contrast
Relative luminance0.09084WCAG 2.x, 0 is black and 1 is white
Perceived brightness85 of 255ITU-R BT.601 weighting
Light or darkDark
Best text colour on this backgroundWhitecontrast 7.46:1
Contrast with white7.46:1WCAG normal text: AAA
Contrast with black2.82:1WCAG normal text: Fail
Greyscale equivalent#555555
Inverted#AAAAAA
Colour vision & accessibility
Distinguishable without hueYesnever rely on hue alone to carry meaning
Contrast with white, large text7.46:1WCAG large text: AAA
Contrast with black, large text2.82:1WCAG large text: Fail
Named colours
Hue familygrey
CSS keyword usableNo exact keyword
Colour harmonies
Complementary#555555
Analogous#555555, #555555
Triadic#555555, #555555
Split complementary#555555, #555555
Tetradic#555555, #555555, #555555
Tints, shades & saturation
Channel breakdown
R85
G85
B85
Red85 (33.3%)
Green85 (33.3%)
Blue85 (33.3%)
Hue0°
Saturation (HSL)0%
Lightness33.33%
Dominant channelNone: the channels are equal (a neutral grey)
Hex per channelR 55 · G 55 · B 55
Keep nerding
Every link below is a page Nerdulator can generate from what it already knows about this value.
Harmonies
Similar named colours
Nerdulate something else
Nothing in mind? Surprise me · today’s page