Recognised as Number
388
- Positive
- Even
- Composite
- 3 digits
388 is an even 3-digit integer and a composite number. It has 6 divisors and a digital root of 1.
Number properties
ParityEvendivisible by 2
SignPositive
PrimalityComposite
Absolute value388
Digit count3
Digit sum19
Digit product192
Multiplicative persistence3times the digit product can be taken before one digit is left
Digital root1repeated digit sum
PalindromicNoreads differently backwards
Happy numberNosquared-digit sums reach 1
Harshad numberNodivisible by its own digit sum
Factors & divisors
Prime factorisation2^2 × 97
Distinct prime factors22, 97
Number of divisors6
Sum of divisors σ(n)686
Aliquot sum298sum of the proper divisors
ClassificationDeficientthe aliquot sum is less than the number
Euler's totient φ(n)192integers below n that share no factor with it
Carmichael function λ(n)96the smallest exponent with aˣ ≡ 1 for every unit; smaller than φ(n) = 192
Möbius function μ(n)0zero, because a prime divides n twice
SquarefreeNohas a repeated prime factor
All divisors1, 2, 4, 97, 194, 3886 in total
Arithmetic
Representations
Decimal388
Binary1100001009 bits
Octal604
Hexadecimal184
Base 36AS
Roman numeralCCCLXXXVIII
In wordsthree hundred and eighty-eight
Ordinalthree hundred and eighty-eighth
Scientific notation3.88 × 10^2
Engineering notation388
In other bases
Ternary112101base 3; the most digit-efficient integer base after e: 6 digits
Quinary3023base 5; one hand: 4 digits
Septenary1063base 7: 4 digits
Nonary471base 9; each digit is two ternary digits: 3 digits
Duodecimal284base 12; divides by 2, 3, 4 and 6, which is why eggs and inches come in twelves: 3 digits
Vigesimalj8base 20; hands and feet, and the Mayan and Yoruba systems: 2 digits
Sexagesimal6:28base 60; Babylonian, and still how an hour and a circle are divided: 2 digits
Balanced ternary1TTT101digits −1, 0 and +1 written T, 0 and 1; negation is swapping T and 1, so no sign is needed
Negabinary11010000100base −2; place values alternate 1, −2, 4, −8, so every integer has exactly one form without a sign
Bit-level
0000000110000100
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 even
Highest set bitbit 8worth 256
Lowest set bitbit 22 trailing zeros
Power of twoNo
Bytes201 84
Gray code101000110n XOR (n >> 1); successive values differ in exactly one bit
At each machine width
16-bit0000000110000100
32-bit00000000000000000000000110000100
64-bit0000000000000000000000000000000000000000000000000000000110000100
One's complement1111111001111011at 16 bits, every bit flipped
Bits reversed0010000110000000at 16 bits
Rotated left by 10000001100001000at 16 bits, wrapping
Shifted left by 11100001000= 776, no wrap
Shifted right by 111000010= 194, discarding the low bit
These bits as a double1.91697471 × 10^-321≈IEEE-754 binary64 reinterpretation of the same 64 bits (subnormal)
Nearest landmarks
Powers & multiples
388 to the power 2150,544
388 to the power 358,411,072
388 to the power 422,663,495,936
388 to the power 58,793,436,423,168
First ten multiples388, 776, 1,164, 1,552, 1,940, 2,328, 2,716, 3,104, 3,492, 3,880
Powers of twoBetween 2^8 (256) and 2^9 (512)
Divisibility tests
Divisible by 2Yes
Divisible by 3No, remainder 1
Divisible by 4Yes
Divisible by 5No, remainder 3
Divisible by 6No, remainder 4
Divisible by 7No, remainder 3
Divisible by 8No, remainder 4
Divisible by 9No, remainder 1
Divisible by 10No, remainder 8
Divisible by 11No, remainder 3
Divisible by 12No, remainder 4
Divisible by 100No, remainder 88
Collatz (3n + 1) trajectory
Steps to reach 1120the total stopping time
Reaches 1Yesthe Collatz conjecture says every positive integer does, but it is unproven
First steps388 → 194 → 97 → 292 → 146 → 73 → 220 → 110 → 55 → 166 → …
Last steps… → 5 → 16 → 8 → 4 → 2 → 1
As a percentage & fraction
As a percentage38,800%
388% as a decimal3.88
388% of 100388
388% of 1,0003,880
As a fraction of 100388/100
Read another way
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Derived from 388
Other readings
Also reads as
#338888 (colour)
- #338888
- Cyan
- Dark
- Nearest: Teal
#338888 is a cyan with RGB values 51, 136, 136 and HSL 180°, 45%, 37%. It is a dark colour, so black text on it reaches 5:1 contrast (AA for normal text). The nearest named colour is Teal.
Colour values
#338888#338888
HEX#338888
HEX (short)#388
RGBrgb(51, 136, 136)
RGB (0–1)0.2, 0.5333, 0.5333
RGB percentages20%, 53.3%, 53.3%
HSLhsl(180, 45.5%, 36.7%)
HSV / HSBhsv(180, 62.5%, 53.3%)
CMYK62.5%, 0%, 0%, 46.7%≈naive device-independent conversion; real print needs an ICC profile
24-bit integer3,377,288
CSS custom property--colour: #338888;
Brightness & contrast
Relative luminance0.2009WCAG 2.x, 0 is black and 1 is white
Perceived brightness117.2 of 255ITU-R BT.601 weighting
Light or darkDark
Best text colour on this backgroundBlackcontrast 5.02:1
Contrast with white4.18:1WCAG normal text: Fail
Contrast with black5.02:1WCAG normal text: AA
Greyscale equivalent#767676
Inverted#CC7777
Colour vision & accessibility
Distinguishable without hueYesnever rely on hue alone to carry meaning
Contrast with white, large text4.18:1WCAG large text: AA
Contrast with black, large text5.02:1WCAG large text: AAA
Named colours
Hue familycyan
CSS keyword usableNo exact keyword
Colour harmonies
Complementary#883333
Analogous#33885E, #335E88
Triadic#883388, #888833
Split complementary#88335E, #885E33
Tetradic#5E3388, #883333, #5E8833
Tints, shades & saturation
Channel breakdown
R51
G136
B136
Red51 (20%)
Green136 (53.3%)
Blue136 (53.3%)
Hue180°
Saturation (HSL)45.45%
Lightness36.67%
Dominant channelGreen and Blue
Hex per channelR 33 · G 88 · B 88
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