Number
85
- Positive
- Odd
- Composite
- 2 digits
85 is an odd 2-digit integer and a composite number. It has 4 divisors and a digital root of 4.
Number properties
ParityOddnot divisible by 2
SignPositive
PrimalityComposite
Absolute value85
Digit count2
Digit sum13
Digital root4repeated digit sum
PalindromicNoreads differently backwards
Happy numberNosquared-digit sums reach 1
Harshad numberNodivisible by its own digit sum
Factors & divisors
Prime factorisation5 × 17
Distinct prime factors25, 17
Number of divisors4
Sum of divisors σ(n)108
Aliquot sum23sum of the proper divisors
ClassificationDeficientthe aliquot sum is less than the number
Euler's totient φ(n)64integers below n that share no factor with it
SquarefreeYesno repeated prime factor
All divisors1, 5, 17, 854 in total
Arithmetic
Representations
Decimal85
Binary10101017 bits
Octal125
Hexadecimal55
Base 362D
Roman numeralLXXXV
In wordseighty-five
Ordinaleighty-fifth
Scientific notation8.5 × 10^1
Engineering notation85
Nearest landmarks
Powers & multiples
85 to the power 27,225
85 to the power 3614,125
85 to the power 452,200,625
85 to the power 54,437,053,125
First ten multiples85, 170, 255, 340, 425, 510, 595, 680, 765, 850
Powers of twoBetween 2^6 (64) and 2^7 (128)
Divisibility tests
Divisible by 2No, remainder 1
Divisible by 3No, remainder 1
Divisible by 4No, remainder 1
Divisible by 5Yes
Divisible by 6No, remainder 1
Divisible by 7No, remainder 1
Divisible by 8No, remainder 5
Divisible by 9No, remainder 4
Divisible by 10No, remainder 5
Divisible by 11No, remainder 8
Divisible by 12No, remainder 1
Divisible by 100No, remainder 85
Collatz (3n + 1) trajectory
Steps to reach 19the total stopping time
Reaches 1Yesthe Collatz conjecture says every positive integer does, but it is unproven
First steps85 → 256 → 128 → 64 → 32 → 16 → 8 → 4 → 2 → 1
As a percentage & fraction
As a percentage8,500%
85% as a decimal0.85
85% of 10085
85% of 1,000850
As a fraction of 10085/100
Read another way
Keep nerding
Every link below is a page Nerdulator can generate from what it already knows about this value.
Derived from 85
Other readings
Nerdulate something else
Nothing in mind? Surprise me · today’s page