Number
49
- Positive
- Odd
- Composite
- Perfect square
- 2 digits
49 is an odd 2-digit integer and a composite number. It has 3 divisors and a digital root of 4.
The canonical address for this page is /49.
Number properties
ParityOddnot divisible by 2
SignPositive
PrimalityComposite
Absolute value49
Digit count2
Digit sum13
Digital root4repeated digit sum
PalindromicNoreads differently backwards
Perfect squareYes, 7²
Happy numberYessquared-digit sums reach 1
Harshad numberNodivisible by its own digit sum
Factors & divisors
Prime factorisation7^2
Distinct prime factors17
Number of divisors3
Sum of divisors σ(n)57
Aliquot sum8sum of the proper divisors
ClassificationDeficientthe aliquot sum is less than the number
Euler's totient φ(n)42integers below n that share no factor with it
SquarefreeNohas a repeated prime factor
All divisors1, 7, 493 in total
Arithmetic
Representations
Decimal49
Binary1100016 bits
Octal61
Hexadecimal31
Base 361D
Roman numeralXLIX
In wordsforty-nine
Ordinalforty-ninth
Scientific notation4.9 × 10^1
Engineering notation49
Nearest landmarks
Powers & multiples
49 to the power 22,401
49 to the power 3117,649
49 to the power 45,764,801
49 to the power 5282,475,249
First ten multiples49, 98, 147, 196, 245, 294, 343, 392, 441, 490
Powers of twoBetween 2^5 (32) and 2^6 (64)
Divisibility tests
Divisible by 2No, remainder 1
Divisible by 3No, remainder 1
Divisible by 4No, remainder 1
Divisible by 5No, remainder 4
Divisible by 6No, remainder 1
Divisible by 7Yes
Divisible by 8No, remainder 1
Divisible by 9No, remainder 4
Divisible by 10No, remainder 9
Divisible by 11No, remainder 5
Divisible by 12No, remainder 1
Divisible by 100No, remainder 49
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 steps49 → 148 → 74 → 37 → 112 → 56 → 28 → 14 → 7 → 22 → …
Last steps… → 5 → 16 → 8 → 4 → 2 → 1
As a percentage & fraction
As a percentage4,900%
49% as a decimal0.49
49% of 10049
49% of 1,000490
As a fraction of 10049/100
Read another way
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Derived from 49
Other readings
Also reads as
#000049 (colour)
- #000049
- Blue
- Dark
- Nearest: Midnight blue
#000049 is a blue with RGB values 0, 0, 73 and HSL 240°, 100%, 14%. It is a dark colour, so white text on it reaches 19.2:1 contrast (AAA for normal text). The nearest named colour is Midnight blue.
Colour values
#000049#000049
HEX#000049
RGBrgb(0, 0, 73)
RGB (0–1)0, 0, 0.2863
RGB percentages0%, 0%, 28.6%
HSLhsl(240, 100%, 14.3%)
HSV / HSBhsv(240, 100%, 28.6%)
CMYK100%, 100%, 0%, 71.4%≈naive device-independent conversion; real print needs an ICC profile
24-bit integer73
CSS custom property--colour: #000049;
Brightness & contrast
Relative luminance0.00481WCAG 2.x, 0 is black and 1 is white
Perceived brightness24.6 of 255ITU-R BT.601 weighting
Light or darkDark
Best text colour on this backgroundWhitecontrast 19.16:1
Contrast with white19.16:1WCAG normal text: AAA
Contrast with black1.1:1WCAG normal text: Fail
Greyscale equivalent#050505
Inverted#FFFFB6
Colour vision & accessibility
Distinguishable without hueYesnever rely on hue alone to carry meaning
Contrast with white, large text19.16:1WCAG large text: AAA
Contrast with black, large text1.1:1WCAG large text: Fail
Named colours
Hue familyblue
CSS keyword usableNo exact keyword
Colour harmonies
Complementary#494900
Analogous#002549, #250049
Triadic#490000, #004900
Split complementary#492500, #254900
Tetradic#490025, #494900, #004925
Tints, shades & saturation
Channel breakdown
R0
G0
B73
Red0 (0%)
Green0 (0%)
Blue73 (28.6%)
Hue240°
Saturation (HSL)100%
Lightness14.31%
Dominant channelBlue
Hex per channelR 00 · G 00 · B 49
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Harmonies
Similar named colours
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