201
CCI
11001001
The number 201 — factors and divisors
Deficient
201 = 3 × 67. It has 4 divisors, adding up to 272.
Its divisors, itself excluded, add up to less than the number.
Laid out as dots
It fits as 3 × 67. The more divisors, the closer to a square.
- Prime factors
- 3 × 67
- Divisors
- 1, 3, 67, 201
- Sum of divisors
- 272
- Sum without itself
- 71
- Coprime below it
- 132
- Digit sum
- 3
- Digital root
- 3
- Roman numeral
- CCI
- Binary
- 11001001
- Octal
- 311
- Hexadecimal
- C9
- Base 36
- 5L
- Bits
- 8 bits
- Collatz steps
- 18 steps · peaks at 1,024
- Prime before
- 199
- Prime after
- 211
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 201 a prime number?
No. It breaks down into 3 × 67.
Q. What are the divisors of 201?
1, 3, 67, 201 — 4 divisors in all, adding up to 272.
Q. How is 201 written in binary?
11001001, which is 8 bits. In hexadecimal it is C9.
Q. How many Collatz steps does 201 take?
It reaches 1 in 18, peaking at 1,024 on the way.