Recognised as Number
720,720
- Positive
- Even
- Composite
- 6 digits
720,720 is an even 6-digit integer and a composite number. It has 240 divisors and a digital root of 9.
Number properties
ParityEvendivisible by 2
SignPositive
PrimalityComposite
Absolute value720,720
Digit count6
Digit sum18
Digit product0zero, because one of the digits is zero
Multiplicative persistence1times the digit product can be taken before one digit is left
Digital root9repeated digit sum
PalindromicNoreads differently backwards
Happy numberNosquared-digit sums reach 1
Harshad numberYesdivisible by its own digit sum
Factors & divisors
Prime factorisation2^4 × 3^2 × 5 × 7 × 11 × 13
Distinct prime factors62, 3, 5, 7, 11, 13
Number of divisors240
Sum of divisors σ(n)3,249,792
Aliquot sum2,529,072sum of the proper divisors
ClassificationAbundantthe aliquot sum exceeds the number
Euler's totient φ(n)138,240integers below n that share no factor with it
Carmichael function λ(n)60the smallest exponent with aˣ ≡ 1 for every unit; smaller than φ(n) = 138,240
Möbius function μ(n)0zero, because a prime divides n twice
SquarefreeNohas a repeated prime factor
All divisors1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 20, 21, 22, 24, 26, 28, 30, 33, 35, 36, 39, 40, 42, 44, 45, 48, 52, 55, 56, 60, 63, 65, 66, 70, 72, 77, 78, 80, 84, 88, 90, 91, 99, 104, 105, 110, 112, 117, 120, 126, 130, 132, 140, 143, 144, 154, 156, 165, 168, 176, 180, 182, 195, 198, 208, 210, 220, 231, 234, 240, 252, 260, 264, 273, 280, 286, 308, 312, 315, 330, 336, 360, 364, 385, 390, 396, 420, 429, 440, 455, 462, 468, 495, 504, 520, 528, 546, 560, 572, 585, 616, 624, 630, 660, 693, 715, 720, 728, 770, 780, 792, 819, 840, 858, 880, 910, 924, 936, 990, 1,001, 1,008, 1,040, 1,092, 1,144, 1,155, 1,170, 1,232, 1,260, 1,287, 1,320, 1,365, 1,386, 1,430, 1,456, 1,540, 1,560, 1,584, 1,638, 1,680, 1,716, 1,820, 1,848, 1,872, 1,980, 2,002, 2,145, 2,184, 2,288, 2,310, 2,340, 2,520, 2,574, 2,640, 2,730, 2,772, 2,860, 3,003, 3,080, 3,120, 3,276, 3,432, 3,465, 3,640, 3,696, 3,960, 4,004, 4,095, 4,290, 4,368, 4,620, 4,680, 5,005, 5,040, 5,148, 5,460, 5,544, 5,720, 6,006, 6,160, 6,435, 6,552, 6,864, 6,930, 7,280, 7,920, 8,008, 8,190, 8,580, 9,009, 9,240, 9,360, 10,010, 10,296, 10,920, 11,088, 11,440, 12,012, 12,870, 13,104, 13,860, 15,015, 16,016, 16,380, 17,160, 18,018, 18,480, 20,020, 20,592, 21,840, 24,024, 25,740, 27,720, 30,030, 32,760, 34,320, 36,036, 40,040, 45,045, 48,048, 51,480, 55,440, 60,060, 65,520, 72,072, 80,080, 90,090, 102,960, 120,120, 144,144, 180,180, 240,240, 360,360, 720,720240 in total
Arithmetic
Representations
Decimal720,720
Binary1010111111110101000020 bits
Octal2577520
HexadecimalAFF50
Base 36FG40
Roman numeralNot defined above 3,999there is no agreed standard notation
In wordsseven hundred and twenty thousand, seven hundred and twenty
Ordinalseven hundred and twenty thousand, seven hundred and twentieth
Scientific notation7.2072 × 10^5
Engineering notation720.72 × 10^3
In other bases
Ternary1100121122100base 3; the most digit-efficient integer base after e: 13 digits
Quinary141030340base 5; one hand: 9 digits
Septenary6061140base 7: 7 digits
Nonary1317570base 9; each digit is two ternary digits: 7 digits
Duodecimal2a9100base 12; divides by 2, 3, 4 and 6, which is why eggs and inches come in twelves: 6 digits
Vigesimal4a1g0base 20; hands and feet, and the Mayan and Yoruba systems: 5 digits
Sexagesimal3:20:12:0base 60; Babylonian, and still how an hour and a circle are divided: 4 digits
Balanced ternary1101T0TT0T100digits −1, 0 and +1 written T, 0 and 1; negation is swapping T and 1, so no sign is needed
Negabinary111110000001101010000base −2; place values alternate 1, −2, 4, −8, so every integer has exactly one form without a sign
Bit-level
00000000000010101111111101010000
Bit length20 bitsto write the magnitude
Set bits12the population count, or Hamming weight
Zero bits8within that length
Bit parityeven12 set bits, so even; not the same as the number itself being even
Highest set bitbit 19worth 524,288
Lowest set bitbit 44 trailing zeros
Power of twoNo
Bytes30a ff 50
Gray code11111000000011111000n XOR (n >> 1); successive values differ in exactly one bit
At each machine width
32-bit00000000000010101111111101010000
64-bit0000000000000000000000000000000000000000000010101111111101010000
One's complement11111111111101010000000010101111at 32 bits, every bit flipped
Bits reversed00001010111111110101000000000000at 32 bits
Rotated left by 100000000000101011111111010100000at 32 bits, wrapping
Shifted left by 1101011111111010100000= 1,441,440, no wrap
Shifted right by 11010111111110101000= 360,360, discarding the low bit
These bits as a double3.56082992 × 10^-318≈IEEE-754 binary64 reinterpretation of the same 64 bits (subnormal)
Nearest landmarks
Powers & multiples
720,720 to the power 2519,437,318,400
720,720 to the power 3374,368,864,117,248,000
720,720 to the power 4269,815,127,746,582,978,560,000
720,720 to the power 5194,461,158,869,517,284,307,763,200,000
First ten multiples720,720, 1,441,440, 2,162,160, 2,882,880, 3,603,600, 4,324,320, 5,045,040, 5,765,760, 6,486,480, 7,207,200
Powers of twoBetween 2^19 (524,288) and 2^20 (1,048,576)
Divisibility tests
Divisible by 2Yes
Divisible by 3Yes
Divisible by 4Yes
Divisible by 5Yes
Divisible by 6Yes
Divisible by 7Yes
Divisible by 8Yes
Divisible by 9Yes
Divisible by 10Yes
Divisible by 11Yes
Divisible by 12Yes
Divisible by 100No, remainder 20
Collatz (3n + 1) trajectory
Steps to reach 1167the total stopping time
Highest value reached720,720
Reaches 1Yesthe Collatz conjecture says every positive integer does, but it is unproven
First steps720,720 → 360,360 → 180,180 → 90,090 → 45,045 → 135,136 → 67,568 → 33,784 → 16,892 → 8,446 → …
Last steps… → 5 → 16 → 8 → 4 → 2 → 1
As a percentage & fraction
As a percentage72,072,000%
720,720% as a decimal7,207.2
720,720% of 100720,720
720,720% of 1,0007,207,200
As a fraction of 100720,720/100
Read another way
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Derived from 720,720
Also reads as
#720720 (colour)
- #720720
- Red
- Dark
- Nearest: Brown
#720720 is a red with RGB values 114, 7, 32 and HSL 346°, 88%, 24%. It is a dark colour, so white text on it reaches 11.9:1 contrast (AAA for normal text). The nearest named colour is Brown.
Colour values
#720720#720720
HEX#720720
RGBrgb(114, 7, 32)
RGB (0–1)0.4471, 0.0275, 0.1255
RGB percentages44.7%, 2.7%, 12.5%
HSLhsl(346, 88.4%, 23.7%)
HSV / HSBhsv(346, 93.9%, 44.7%)
CMYK0%, 93.9%, 71.9%, 55.3%≈naive device-independent conversion; real print needs an ICC profile
24-bit integer7,472,928
CSS custom property--colour: #720720;
Brightness & contrast
Relative luminance0.03834WCAG 2.x, 0 is black and 1 is white
Perceived brightness63.5 of 255ITU-R BT.601 weighting
Light or darkDark
Best text colour on this backgroundWhitecontrast 11.89:1
Contrast with white11.89:1WCAG normal text: AAA
Contrast with black1.77:1WCAG normal text: Fail
Greyscale equivalent#202020
Inverted#8DF8DF
Colour vision & accessibility
Distinguishable without hueShifts in lightness toonever rely on hue alone to carry meaning
Contrast with white, large text11.89:1WCAG large text: AAA
Contrast with black, large text1.77:1WCAG large text: Fail
Named colours
Hue familyred
CSS keyword usableNo exact keyword
Colour harmonies
Complementary#077259
Analogous#720755, #722407
Triadic#207207, #072072
Split complementary#077224, #075572
Tetradic#557207, #077259, #240772
Tints, shades & saturation
Channel breakdown
R114
G7
B32
Red114 (44.7%)
Green7 (2.7%)
Blue32 (12.5%)
Hue345.98°
Saturation (HSL)88.43%
Lightness23.73%
Dominant channelRed
Hex per channelR 72 · G 07 · B 20
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