216
CCXVI
11011000
The number 216 — factors and divisors
Abundant
216 = 2³ × 3³. It has 16 divisors, adding up to 600.
Its divisors, itself excluded, add up to more than the number.
Families it belongs to
Cube
A number times itself three times — the dots stack into a cube.
Laid out as dots
It fits as 12 × 18. The more divisors, the closer to a square.
- Prime factors
- 2³ × 3³
- Divisors
- 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 27, 36, 54, 72, 108, 216
- Sum of divisors
- 600
- Sum without itself
- 384
- Coprime below it
- 72
- Digit sum
- 9
- Digital root
- 9
- Roman numeral
- CCXVI
- Binary
- 11011000
- Octal
- 330
- Hexadecimal
- D8
- Base 36
- 60
- Bits
- 8 bits
- Collatz steps
- 114 steps · peaks at 9,232
- Prime before
- 211
- Prime after
- 223
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 216 a prime number?
No. It breaks down into 2³ × 3³.
Q. What are the divisors of 216?
1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 27, 36, 54, 72, 108, 216 — 16 divisors in all, adding up to 600.
Q. How is 216 written in binary?
11011000, which is 8 bits. In hexadecimal it is D8.
Q. How many Collatz steps does 216 take?
It reaches 1 in 114, peaking at 9,232 on the way.