Number
631
- Positive
- Odd
- Prime
- 3 digits
631 is an odd 3-digit integer and a prime number. It has 2 divisors and a digital root of 1.
Number properties
ParityOddnot divisible by 2
SignPositive
PrimalityPrime
Absolute value631
Digit count3
Digit sum10
Digital root1repeated digit sum
PalindromicNoreads differently backwards
Happy numberNosquared-digit sums reach 1
Harshad numberNodivisible by its own digit sum
Factors & divisors
Prime factorisation631
Distinct prime factors1631
Number of divisors2
Sum of divisors σ(n)632
Aliquot sum1sum of the proper divisors
ClassificationDeficientthe aliquot sum is less than the number
Euler's totient φ(n)630integers below n that share no factor with it
SquarefreeYesno repeated prime factor
All divisors1, 6312 in total
Arithmetic
Representations
Decimal631
Binary100111011110 bits
Octal1167
Hexadecimal277
Base 36HJ
Roman numeralDCXXXI
In wordssix hundred and thirty-one
Ordinalsix hundred and thirty-first
Scientific notation6.31 × 10^2
Engineering notation631
Nearest landmarks
Powers & multiples
631 to the power 2398,161
631 to the power 3251,239,591
631 to the power 4158,532,181,921
631 to the power 5100,033,806,792,151
First ten multiples631, 1,262, 1,893, 2,524, 3,155, 3,786, 4,417, 5,048, 5,679, 6,310
Powers of twoBetween 2^9 (512) and 2^10 (1,024)
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 1
Divisible by 8No, remainder 7
Divisible by 9No, remainder 1
Divisible by 10No, remainder 1
Divisible by 11No, remainder 4
Divisible by 12No, remainder 7
Divisible by 100No, remainder 31
Collatz (3n + 1) trajectory
Steps to reach 138the total stopping time
Reaches 1Yesthe Collatz conjecture says every positive integer does, but it is unproven
First steps631 → 1,894 → 947 → 2,842 → 1,421 → 4,264 → 2,132 → 1,066 → 533 → 1,600 → …
Last steps… → 5 → 16 → 8 → 4 → 2 → 1
As a percentage & fraction
As a percentage63,100%
631% as a decimal6.31
631% of 100631
631% of 1,0006,310
As a fraction of 100631/100
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Derived from 631
Other readings
Also reads as
#663311 (colour)
- #663311
- Orange
- Dark
- Nearest: Saddle brown
#663311 is a orange with RGB values 102, 51, 17 and HSL 24°, 71%, 23%. It is a dark colour, so white text on it reaches 10.3:1 contrast (AAA for normal text). The nearest named colour is Saddle brown.
Colour values
#663311#663311
HEX#663311
HEX (short)#631
RGBrgb(102, 51, 17)
RGB (0–1)0.4, 0.2, 0.0667
RGB percentages40%, 20%, 6.7%
HSLhsl(24, 71.4%, 23.3%)
HSV / HSBhsv(24, 83.3%, 40%)
CMYK0%, 50%, 83.3%, 60%≈naive device-independent conversion; real print needs an ICC profile
24-bit integer6,697,745
CSS custom property--colour: #663311;
Brightness & contrast
Relative luminance0.05233WCAG 2.x, 0 is black and 1 is white
Perceived brightness68.3 of 255ITU-R BT.601 weighting
Light or darkDark
Best text colour on this backgroundWhitecontrast 10.26:1
Contrast with white10.26:1WCAG normal text: AAA
Contrast with black2.05:1WCAG normal text: Fail
Greyscale equivalent#3B3B3B
Inverted#99CCEE
Colour vision & accessibility
Distinguishable without hueYesnever rely on hue alone to carry meaning
Contrast with white, large text10.26:1WCAG large text: AAA
Contrast with black, large text2.05:1WCAG large text: Fail
Named colours
Hue familyorange
CSS keyword usableNo exact keyword
Colour harmonies
Complementary#114466
Analogous#661119, #665D11
Triadic#116633, #331166
Split complementary#11665D, #111A66
Tetradic#1A6611, #114466, #5E1166
Tints, shades & saturation
Channel breakdown
R102
G51
B17
Red102 (40%)
Green51 (20%)
Blue17 (6.7%)
Hue24°
Saturation (HSL)71.43%
Lightness23.33%
Dominant channelRed
Hex per channelR 66 · G 33 · B 11
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