220
CCXX
11011100
The number 220 — factors and divisors
Abundant
220 = 2² × 5 × 11. It has 12 divisors, adding up to 504.
Its divisors, itself excluded, add up to more than the number.
Laid out as dots
It fits as 11 × 20. The more divisors, the closer to a square.
- Prime factors
- 2² × 5 × 11
- Divisors
- 1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, 220
- Sum of divisors
- 504
- Sum without itself
- 284
- Coprime below it
- 80
- Digit sum
- 4
- Digital root
- 4
- Roman numeral
- CCXX
- Binary
- 11011100
- Octal
- 334
- Hexadecimal
- DC
- Base 36
- 64
- 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 220 a prime number?
No. It breaks down into 2² × 5 × 11.
Q. What are the divisors of 220?
1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, 220 — 12 divisors in all, adding up to 504.
Q. How is 220 written in binary?
11011100, which is 8 bits. In hexadecimal it is DC.
Q. How many Collatz steps does 220 take?
It reaches 1 in 114, peaking at 9,232 on the way.