Number
131
- Positive
- Odd
- Prime
- 3 digits
131 is an odd 3-digit integer and a prime number. It has 2 divisors and a digital root of 5.
Number properties
ParityOddnot divisible by 2
SignPositive
PrimalityPrime
Absolute value131
Digit count3
Digit sum5
Digital root5repeated digit sum
PalindromicYesreads the same backwards
Happy numberNosquared-digit sums reach 1
Harshad numberNodivisible by its own digit sum
Factors & divisors
Prime factorisation131
Distinct prime factors1131
Number of divisors2
Sum of divisors σ(n)132
Aliquot sum1sum of the proper divisors
ClassificationDeficientthe aliquot sum is less than the number
Euler's totient φ(n)130integers below n that share no factor with it
SquarefreeYesno repeated prime factor
All divisors1, 1312 in total
Arithmetic
Representations
Decimal131
Binary100000118 bits
Octal203
Hexadecimal83
Base 363N
Roman numeralCXXXI
In wordsone hundred and thirty-one
Ordinalone hundred and thirty-first
Scientific notation1.31 × 10^2
Engineering notation131
Nearest landmarks
Powers & multiples
131 to the power 217,161
131 to the power 32,248,091
131 to the power 4294,499,921
131 to the power 538,579,489,651
First ten multiples131, 262, 393, 524, 655, 786, 917, 1,048, 1,179, 1,310
Powers of twoBetween 2^7 (128) and 2^8 (256)
Divisibility tests
Divisible by 2No, remainder 1
Divisible by 3No, remainder 2
Divisible by 4No, remainder 3
Divisible by 5No, remainder 1
Divisible by 6No, remainder 5
Divisible by 7No, remainder 5
Divisible by 8No, remainder 3
Divisible by 9No, remainder 5
Divisible by 10No, remainder 1
Divisible by 11No, remainder 10
Divisible by 12No, remainder 11
Divisible by 100No, remainder 31
Collatz (3n + 1) trajectory
Steps to reach 128the total stopping time
Reaches 1Yesthe Collatz conjecture says every positive integer does, but it is unproven
First steps131 → 394 → 197 → 592 → 296 → 148 → 74 → 37 → 112 → 56 → …
Last steps… → 5 → 16 → 8 → 4 → 2 → 1
As a percentage & fraction
As a percentage13,100%
131% as a decimal1.31
131% of 100131
131% of 1,0001,310
As a fraction of 100131/100
Read another way
Keep nerding
Every link below is a page Nerdulator can generate from what it already knows about this value.
Derived from 131
Other readings
Also reads as
#113311 (colour)
- #113311
- Green
- Dark
- Nearest: Dark slate grey
#113311 is a green with RGB values 17, 51, 17 and HSL 120°, 50%, 13%. It is a dark colour, so white text on it reaches 13.9:1 contrast (AAA for normal text). The nearest named colour is Dark slate grey.
Colour values
#113311#113311
HEX#113311
HEX (short)#131
RGBrgb(17, 51, 17)
RGB (0–1)0.0667, 0.2, 0.0667
RGB percentages6.7%, 20%, 6.7%
HSLhsl(120, 50%, 13.3%)
HSV / HSBhsv(120, 66.7%, 20%)
CMYK66.7%, 0%, 66.7%, 80%≈naive device-independent conversion; real print needs an ICC profile
24-bit integer1,127,185
CSS custom property--colour: #113311;
Brightness & contrast
Relative luminance0.02527WCAG 2.x, 0 is black and 1 is white
Perceived brightness40.6 of 255ITU-R BT.601 weighting
Light or darkDark
Best text colour on this backgroundWhitecontrast 13.95:1
Contrast with white13.95:1WCAG normal text: AAA
Contrast with black1.51:1WCAG normal text: Fail
Greyscale equivalent#292929
Inverted#EECCEE
Colour vision & accessibility
Distinguishable without hueYesnever rely on hue alone to carry meaning
Contrast with white, large text13.95:1WCAG large text: AAA
Contrast with black, large text1.51:1WCAG large text: Fail
Named colours
Hue familygreen
CSS keyword usableNo exact keyword
Colour harmonies
Complementary#331133
Analogous#223311, #113322
Triadic#111133, #331111
Split complementary#221133, #331122
Tetradic#112233, #331133, #332211
Tints, shades & saturation
Channel breakdown
R17
G51
B17
Red17 (6.7%)
Green51 (20%)
Blue17 (6.7%)
Hue120°
Saturation (HSL)50%
Lightness13.33%
Dominant channelGreen
Hex per channelR 11 · G 33 · B 11
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