Recognised as Number
321
- Positive
- Odd
- Composite
- 3 digits
321 is an odd 3-digit integer and a composite number. It has 4 divisors and a digital root of 6.
Number properties
ParityOddnot divisible by 2
SignPositive
PrimalityComposite
Absolute value321
Digit count3
Digit sum6
Digit product6
Multiplicative persistence1times the digit product can be taken before one digit is left
Digital root6repeated digit sum
PalindromicNoreads differently backwards
Happy numberNosquared-digit sums reach 1
Harshad numberNodivisible by its own digit sum
Factors & divisors
Prime factorisation3 × 107
Distinct prime factors23, 107
Number of divisors4
Sum of divisors σ(n)432
Aliquot sum111sum of the proper divisors
ClassificationDeficientthe aliquot sum is less than the number
Euler's totient φ(n)212integers below n that share no factor with it
Carmichael function λ(n)106the smallest exponent with aˣ ≡ 1 for every unit; smaller than φ(n) = 212
Möbius function μ(n)+12 distinct prime factors, an even number of them
SquarefreeYesno repeated prime factor
All divisors1, 3, 107, 3214 in total
Arithmetic
Representations
Decimal321
Binary1010000019 bits
Octal501
Hexadecimal141
Base 368X
Roman numeralCCCXXI
In wordsthree hundred and twenty-one
Ordinalthree hundred and twenty-first
Scientific notation3.21 × 10^2
Engineering notation321
In other bases
Ternary102220base 3; the most digit-efficient integer base after e: 6 digits
Quinary2241base 5; one hand: 4 digits
Septenary636base 7: 3 digits
Nonary386base 9; each digit is two ternary digits: 3 digits
Duodecimal229base 12; divides by 2, 3, 4 and 6, which is why eggs and inches come in twelves: 3 digits
Vigesimalg1base 20; hands and feet, and the Mayan and Yoruba systems: 2 digits
Sexagesimal5:21base 60; Babylonian, and still how an hour and a circle are divided: 2 digits
Balanced ternary1100T0digits −1, 0 and +1 written T, 0 and 1; negation is swapping T and 1, so no sign is needed
Negabinary101000001base −2; place values alternate 1, −2, 4, −8, so every integer has exactly one form without a sign
Bit-level
0000000101000001
Bit length9 bitsto write the magnitude
Set bits3the population count, or Hamming weight
Zero bits6within that length
Bit parityodd3 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 41
Gray code111100001n XOR (n >> 1); successive values differ in exactly one bit
At each machine width
16-bit0000000101000001
32-bit00000000000000000000000101000001
64-bit0000000000000000000000000000000000000000000000000000000101000001
One's complement1111111010111110at 16 bits, every bit flipped
Bits reversed1000001010000000at 16 bits
Rotated left by 10000001010000010at 16 bits, wrapping
Shifted left by 11010000010= 642, no wrap
Shifted right by 110100000= 160, discarding the low bit
These bits as a double1.58595072 × 10^-321≈IEEE-754 binary64 reinterpretation of the same 64 bits (subnormal)
Nearest landmarks
Powers & multiples
321 to the power 2103,041
321 to the power 333,076,161
321 to the power 410,617,447,681
321 to the power 53,408,200,705,601
First ten multiples321, 642, 963, 1,284, 1,605, 1,926, 2,247, 2,568, 2,889, 3,210
Powers of twoBetween 2^8 (256) and 2^9 (512)
Divisibility tests
Divisible by 2No, remainder 1
Divisible by 3Yes
Divisible by 4No, remainder 1
Divisible by 5No, remainder 1
Divisible by 6No, remainder 3
Divisible by 7No, remainder 6
Divisible by 8No, remainder 1
Divisible by 9No, remainder 6
Divisible by 10No, remainder 1
Divisible by 11No, remainder 2
Divisible by 12No, remainder 9
Divisible by 100No, remainder 21
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 steps321 → 964 → 482 → 241 → 724 → 362 → 181 → 544 → 272 → 136 → …
Last steps… → 5 → 16 → 8 → 4 → 2 → 1
As a percentage & fraction
As a percentage32,100%
321% as a decimal3.21
321% of 100321
321% of 1,0003,210
As a fraction of 100321/100
Read another way
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Derived from 321
Other readings
Also reads as
#332211 (colour)
- #332211
- Orange
- Dark
- Nearest: Black
#332211 is a orange with RGB values 51, 34, 17 and HSL 30°, 50%, 13%. It is a dark colour, so white text on it reaches 15.2:1 contrast (AAA for normal text). The nearest named colour is Black.
Colour values
#332211#332211
HEX#332211
HEX (short)#321
RGBrgb(51, 34, 17)
RGB (0–1)0.2, 0.1333, 0.0667
RGB percentages20%, 13.3%, 6.7%
HSLhsl(30, 50%, 13.3%)
HSV / HSBhsv(30, 66.7%, 20%)
CMYK0%, 33.3%, 66.7%, 80%≈naive device-independent conversion; real print needs an ICC profile
24-bit integer3,351,057
CSS custom property--colour: #332211;
Brightness & contrast
Relative luminance0.01888WCAG 2.x, 0 is black and 1 is white
Perceived brightness38.6 of 255ITU-R BT.601 weighting
Light or darkDark
Best text colour on this backgroundWhitecontrast 15.24:1
Contrast with white15.24:1WCAG normal text: AAA
Contrast with black1.38:1WCAG normal text: Fail
Greyscale equivalent#242424
Inverted#CCDDEE
Colour vision & accessibility
Distinguishable without hueYesnever rely on hue alone to carry meaning
Contrast with white, large text15.24:1WCAG large text: AAA
Contrast with black, large text1.38:1WCAG large text: Fail
Named colours
Hue familyorange
CSS keyword usableNo exact keyword
Colour harmonies
Complementary#112233
Analogous#331111, #333311
Triadic#113322, #221133
Split complementary#113333, #111133
Tetradic#113311, #112233, #331133
Tints, shades & saturation
Channel breakdown
R51
G34
B17
Red51 (20%)
Green34 (13.3%)
Blue17 (6.7%)
Hue30°
Saturation (HSL)50%
Lightness13.33%
Dominant channelRed
Hex per channelR 33 · G 22 · B 11
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Harmonies
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