Recognised as Number

47

Positive
Odd
Prime
2 digits

47 is an odd 2-digit integer and a prime number. It has 2 divisors and a digital root of 2.

Number properties

ParityOddnot divisible by 2

SignPositive

PrimalityPrime

Absolute value47

Digit count2

Digit sum11

Digit product28

Multiplicative persistence3times the digit product can be taken before one digit is left

Digital root2repeated digit sum

PalindromicNoreads differently backwards

Happy numberNosquared-digit sums reach 1

Harshad numberNodivisible by its own digit sum

Factors & divisors

Prime factorisation47

Distinct prime factors147

Number of divisors2

Sum of divisors σ(n)48

Aliquot sum1sum of the proper divisors

ClassificationDeficientthe aliquot sum is less than the number

Euler's totient φ(n)46integers below n that share no factor with it

Carmichael function λ(n)46the smallest exponent with aˣ ≡ 1 for every unit coprime to n

Möbius function μ(n)−11 distinct prime factor, an odd number of them

SquarefreeYesno repeated prime factor

All divisors1, 472 in total

Arithmetic

Previous number46

Next number48

Double94

Half23.5

Square2,209

Cube103,823

Square root6.8556546≈irrational, shown to 9 decimal places

Cube root3.60882608≈

Negation-47

Reciprocal0.0212765957≈

47 factorial258,623,241,511,168,180,642,964,355,153,611,979,969,197,632,389,120,000,000,000

Representations

Decimal47

Binary1011116 bits

Octal57

Hexadecimal2F

Base 361B

Roman numeralXLVII

In wordsforty-seven

Ordinalforty-seventh

Scientific notation4.7 × 10^1

Engineering notation47

In other bases

Ternary1202base 3; the most digit-efficient integer base after e: 4 digits

Quinary142base 5; one hand: 3 digits

Septenary65base 7: 2 digits

Nonary52base 9; each digit is two ternary digits: 2 digits

Duodecimal3bbase 12; divides by 2, 3, 4 and 6, which is why eggs and inches come in twelves: 2 digits

Vigesimal27base 20; hands and feet, and the Mayan and Yoruba systems: 2 digits

Sexagesimal47base 60; Babylonian, and still how an hour and a circle are divided: 1 digit

Balanced ternary1TT1Tdigits −1, 0 and +1 written T, 0 and 1; negation is swapping T and 1, so no sign is needed

Negabinary1110011base −2; place values alternate 1, −2, 4, −8, so every integer has exactly one form without a sign

Bit-level

00101111

Bit length6 bitsto write the magnitude

Set bits5the population count, or Hamming weight

Zero bits1within that length

Bit parityodd5 set bits, so odd; not the same as the number itself being odd

Highest set bitbit 5worth 32

Lowest set bitbit 00 trailing zeros

Power of twoNo

Bytes12f

Gray code111000n XOR (n >> 1); successive values differ in exactly one bit

At each machine width

8-bit00101111

16-bit0000000000101111

32-bit00000000000000000000000000101111

64-bit0000000000000000000000000000000000000000000000000000000000101111

One's complement11010000at 8 bits, every bit flipped

Bits reversed11110100at 8 bits

Rotated left by 101011110at 8 bits, wrapping

Shifted left by 11011110= 94, no wrap

Shifted right by 110111= 23, discarding the low bit

These bits as a double2.32210854 × 10^-322≈IEEE-754 binary64 reinterpretation of the same 64 bits (subnormal)

Nearest landmarks

Next prime53+6

Previous prime43−4

Distance to nearest prime0, it is prime

Nearest square below36

Nearest square above49

Powers & multiples

47 to the power 22,209

47 to the power 3103,823

47 to the power 44,879,681

47 to the power 5229,345,007

First ten multiples47, 94, 141, 188, 235, 282, 329, 376, 423, 470

Powers of twoBetween 2^5 (32) and 2^6 (64)

Divisibility tests

Divisible by 2No, remainder 1

Divisible by 3No, remainder 2

Divisible by 4No, remainder 3

Divisible by 5No, remainder 2

Divisible by 6No, remainder 5

Divisible by 7No, remainder 5

Divisible by 8No, remainder 7

Divisible by 9No, remainder 2

Divisible by 10No, remainder 7

Divisible by 11No, remainder 3

Divisible by 12No, remainder 11

Divisible by 100No, remainder 47

Collatz (3n + 1) trajectory

Steps to reach 1104the total stopping time

Highest value reached9,232196× the starting value

Reaches 1Yesthe Collatz conjecture says every positive integer does, but it is unproven

First steps47 → 142 → 71 → 214 → 107 → 322 → 161 → 484 → 242 → 121 → …

Last steps… → 5 → 16 → 8 → 4 → 2 → 1

As a percentage & fraction

As a percentage4,700%

47% as a decimal0.47

47% of 10047

47% of 1,000470

As a fraction of 10047/100

Read another way

As seconds47 seconds

As bytes47 B

As a 24-bit colour#00002F

Keep nerding

Every link below is a page Nerdulator can generate from what it already knows about this value.

47