Number
129
- Positive
- Odd
- Composite
- 3 digits
129 is an odd 3-digit integer and a composite number. It has 4 divisors and a digital root of 3.
Number properties
ParityOddnot divisible by 2
SignPositive
PrimalityComposite
Absolute value129
Digit count3
Digit sum12
Digital root3repeated digit sum
PalindromicNoreads differently backwards
Happy numberYessquared-digit sums reach 1
Harshad numberNodivisible by its own digit sum
Factors & divisors
Prime factorisation3 × 43
Distinct prime factors23, 43
Number of divisors4
Sum of divisors σ(n)176
Aliquot sum47sum of the proper divisors
ClassificationDeficientthe aliquot sum is less than the number
Euler's totient φ(n)84integers below n that share no factor with it
SquarefreeYesno repeated prime factor
All divisors1, 3, 43, 1294 in total
Arithmetic
Representations
Decimal129
Binary100000018 bits
Octal201
Hexadecimal81
Base 363L
Roman numeralCXXIX
In wordsone hundred and twenty-nine
Ordinalone hundred and twenty-ninth
Scientific notation1.29 × 10^2
Engineering notation129
Nearest landmarks
Powers & multiples
129 to the power 216,641
129 to the power 32,146,689
129 to the power 4276,922,881
129 to the power 535,723,051,649
First ten multiples129, 258, 387, 516, 645, 774, 903, 1,032, 1,161, 1,290
Powers of twoBetween 2^7 (128) and 2^8 (256)
Divisibility tests
Divisible by 2No, remainder 1
Divisible by 3Yes
Divisible by 4No, remainder 1
Divisible by 5No, remainder 4
Divisible by 6No, remainder 3
Divisible by 7No, remainder 3
Divisible by 8No, remainder 1
Divisible by 9No, remainder 3
Divisible by 10No, remainder 9
Divisible by 11No, remainder 8
Divisible by 12No, remainder 9
Divisible by 100No, remainder 29
Collatz (3n + 1) trajectory
Steps to reach 1121the total stopping time
Reaches 1Yesthe Collatz conjecture says every positive integer does, but it is unproven
First steps129 → 388 → 194 → 97 → 292 → 146 → 73 → 220 → 110 → 55 → …
Last steps… → 5 → 16 → 8 → 4 → 2 → 1
As a percentage & fraction
As a percentage12,900%
129% as a decimal1.29
129% of 100129
129% of 1,0001,290
As a fraction of 100129/100
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Derived from 129
Other readings
Also reads as
#112299 (colour)
- #112299
- Blue
- Dark
- Nearest: Navy
#112299 is a blue with RGB values 17, 34, 153 and HSL 233°, 80%, 33%. It is a dark colour, so white text on it reaches 12.3:1 contrast (AAA for normal text). The nearest named colour is Navy.
Colour values
#112299#112299
HEX#112299
HEX (short)#129
RGBrgb(17, 34, 153)
RGB (0–1)0.0667, 0.1333, 0.6
RGB percentages6.7%, 13.3%, 60%
HSLhsl(232.5, 80%, 33.3%)
HSV / HSBhsv(232.5, 88.9%, 60%)
CMYK88.9%, 77.8%, 0%, 40%≈naive device-independent conversion; real print needs an ICC profile
24-bit integer1,122,969
CSS custom property--colour: #112299;
Brightness & contrast
Relative luminance0.03563WCAG 2.x, 0 is black and 1 is white
Perceived brightness58.6 of 255ITU-R BT.601 weighting
Light or darkDark
Best text colour on this backgroundWhitecontrast 12.26:1
Contrast with white12.26:1WCAG normal text: AAA
Contrast with black1.71:1WCAG normal text: Fail
Greyscale equivalent#272727
Inverted#EEDD66
Colour vision & accessibility
Distinguishable without hueShifts in lightness toonever rely on hue alone to carry meaning
Contrast with white, large text12.26:1WCAG large text: AAA
Contrast with black, large text1.71:1WCAG large text: Fail
Named colours
Hue familyblue
CSS keyword usableNo exact keyword
Colour harmonies
Complementary#998811
Analogous#116699, #441199
Triadic#991122, #229911
Split complementary#994411, #669911
Tetradic#991166, #998811, #119944
Tints, shades & saturation
Channel breakdown
R17
G34
B153
Red17 (6.7%)
Green34 (13.3%)
Blue153 (60%)
Hue232.5°
Saturation (HSL)80%
Lightness33.33%
Dominant channelBlue
Hex per channelR 11 · G 22 · B 99
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