86
LXXXVI
1010110
The number 86 — factors and divisors
Deficient
86 = 2 × 43. It has 4 divisors, adding up to 132.
Its divisors, itself excluded, add up to less than the number.
Laid out as dots
It fits as 2 × 43. The more divisors, the closer to a square.
- Prime factors
- 2 × 43
- Divisors
- 1, 2, 43, 86
- Sum of divisors
- 132
- Sum without itself
- 46
- Coprime below it
- 42
- Digit sum
- 14
- Digital root
- 5
- Roman numeral
- LXXXVI
- Binary
- 1010110
- Octal
- 126
- Hexadecimal
- 56
- Base 36
- 2E
- Bits
- 7 bits
- Collatz steps
- 30 steps · peaks at 196
- Prime before
- 83
- Prime after
- 89
The grid
Ten per row, twenty rows. The filled cells are primes — you can see the multiples of 2 and 5 drop out in columns.
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Numbers either side
How to read this
- The prime factors are what the number is made of. The count and sum of divisors both follow from them.
- Add the divisors, take the number away, and you get perfect, abundant or deficient.
- The length of the binary form is the bit count. 255 taking eight digits is what a byte is.
- Collatz: halve it if even, triple it and add one if odd. The count is how many moves reach 1.
Frequently asked questions
Q. Is 86 a prime number?
No. It breaks down into 2 × 43.
Q. What are the divisors of 86?
1, 2, 43, 86 — 4 divisors in all, adding up to 132.
Q. How is 86 written in binary?
1010110, which is 7 bits. In hexadecimal it is 56.
Q. How many Collatz steps does 86 take?
It reaches 1 in 30, peaking at 196 on the way.