Recognised as Number
331
- Positive
- Odd
- Prime
- 3 digits
331 is an odd 3-digit integer and a prime number. It has 2 divisors and a digital root of 7.
Number properties
ParityOddnot divisible by 2
SignPositive
PrimalityPrime
Absolute value331
Digit count3
Digit sum7
Digit product9
Multiplicative persistence1times the digit product can be taken before one digit is left
Digital root7repeated digit sum
PalindromicNoreads differently backwards
Happy numberYessquared-digit sums reach 1
Harshad numberNodivisible by its own digit sum
Factors & divisors
Prime factorisation331
Distinct prime factors1331
Number of divisors2
Sum of divisors σ(n)332
Aliquot sum1sum of the proper divisors
ClassificationDeficientthe aliquot sum is less than the number
Euler's totient φ(n)330integers below n that share no factor with it
Carmichael function λ(n)330the smallest exponent with aˣ ≡ 1 for every unit coprime to n
Möbius function μ(n)−11 distinct prime factor, an odd number of them
SquarefreeYesno repeated prime factor
All divisors1, 3312 in total
Arithmetic
Representations
Decimal331
Binary1010010119 bits
Octal513
Hexadecimal14B
Base 3697
Roman numeralCCCXXXI
In wordsthree hundred and thirty-one
Ordinalthree hundred and thirty-first
Scientific notation3.31 × 10^2
Engineering notation331
In other bases
Ternary110021base 3; the most digit-efficient integer base after e: 6 digits
Quinary2311base 5; one hand: 4 digits
Septenary652base 7: 3 digits
Nonary407base 9; each digit is two ternary digits: 3 digits
Duodecimal237base 12; divides by 2, 3, 4 and 6, which is why eggs and inches come in twelves: 3 digits
Vigesimalgbbase 20; hands and feet, and the Mayan and Yoruba systems: 2 digits
Sexagesimal5:31base 60; Babylonian, and still how an hour and a circle are divided: 2 digits
Balanced ternary1101T1digits −1, 0 and +1 written T, 0 and 1; negation is swapping T and 1, so no sign is needed
Negabinary101011111base −2; place values alternate 1, −2, 4, −8, so every integer has exactly one form without a sign
Bit-level
0000000101001011
Bit length9 bitsto write the magnitude
Set bits5the population count, or Hamming weight
Zero bits4within that length
Bit parityodd5 set bits, so odd; not the same as the number itself being odd
Highest set bitbit 8worth 256
Lowest set bitbit 00 trailing zeros
Power of twoNo
Bytes201 4b
Gray code111101110n XOR (n >> 1); successive values differ in exactly one bit
At each machine width
16-bit0000000101001011
32-bit00000000000000000000000101001011
64-bit0000000000000000000000000000000000000000000000000000000101001011
One's complement1111111010110100at 16 bits, every bit flipped
Bits reversed1101001010000000at 16 bits
Rotated left by 10000001010010110at 16 bits, wrapping
Shifted left by 11010010110= 662, no wrap
Shifted right by 110100101= 165, discarding the low bit
These bits as a double1.63535729 × 10^-321≈IEEE-754 binary64 reinterpretation of the same 64 bits (subnormal)
Nearest landmarks
Powers & multiples
331 to the power 2109,561
331 to the power 336,264,691
331 to the power 412,003,612,721
331 to the power 53,973,195,810,651
First ten multiples331, 662, 993, 1,324, 1,655, 1,986, 2,317, 2,648, 2,979, 3,310
Powers of twoBetween 2^8 (256) and 2^9 (512)
Divisibility tests
Divisible by 2No, remainder 1
Divisible by 3No, remainder 1
Divisible by 4No, remainder 3
Divisible by 5No, remainder 1
Divisible by 6No, remainder 1
Divisible by 7No, remainder 2
Divisible by 8No, remainder 3
Divisible by 9No, remainder 7
Divisible by 10No, remainder 1
Divisible by 11No, remainder 1
Divisible by 12No, remainder 7
Divisible by 100No, remainder 31
Collatz (3n + 1) trajectory
Steps to reach 124the total stopping time
Reaches 1Yesthe Collatz conjecture says every positive integer does, but it is unproven
First steps331 → 994 → 497 → 1,492 → 746 → 373 → 1,120 → 560 → 280 → 140 → …
Last steps… → 5 → 16 → 8 → 4 → 2 → 1
As a percentage & fraction
As a percentage33,100%
331% as a decimal3.31
331% of 100331
331% of 1,0003,310
As a fraction of 100331/100
Read another way
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Derived from 331
Other readings
Also reads as
#333311 (colour)
- #333311
- Yellow
- Dark
- Nearest: Dark olivegreen
#333311 is a yellow with RGB values 51, 51, 17 and HSL 60°, 50%, 13%. It is a dark colour, so white text on it reaches 12.9:1 contrast (AAA for normal text). The nearest named colour is Dark olivegreen.
Colour values
#333311#333311
HEX#333311
HEX (short)#331
RGBrgb(51, 51, 17)
RGB (0–1)0.2, 0.2, 0.0667
RGB percentages20%, 20%, 6.7%
HSLhsl(60, 50%, 13.3%)
HSV / HSBhsv(60, 66.7%, 20%)
CMYK0%, 0%, 66.7%, 80%≈naive device-independent conversion; real print needs an ICC profile
24-bit integer3,355,409
CSS custom property--colour: #333311;
Brightness & contrast
Relative luminance0.03112WCAG 2.x, 0 is black and 1 is white
Perceived brightness48.3 of 255ITU-R BT.601 weighting
Light or darkDark
Best text colour on this backgroundWhitecontrast 12.94:1
Contrast with white12.94:1WCAG normal text: AAA
Contrast with black1.62:1WCAG normal text: Fail
Greyscale equivalent#313131
Inverted#CCCCEE
Colour vision & accessibility
Distinguishable without hueYesnever rely on hue alone to carry meaning
Contrast with white, large text12.94:1WCAG large text: AAA
Contrast with black, large text1.62:1WCAG large text: Fail
Named colours
Hue familyyellow
CSS keyword usableNo exact keyword
Colour harmonies
Complementary#111133
Analogous#332211, #223311
Triadic#113333, #331133
Split complementary#112233, #221133
Tetradic#113322, #111133, #331122
Tints, shades & saturation
Channel breakdown
R51
G51
B17
Red51 (20%)
Green51 (20%)
Blue17 (6.7%)
Hue60°
Saturation (HSL)50%
Lightness13.33%
Dominant channelRed and Green
Hex per channelR 33 · G 33 · B 11
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Harmonies
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