The number 201
201 is a composite number with 4 divisors. Its prime factorisation is 3 × 67. Divisors (4): 1, 3, 67, 201.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 201: a Harshad number: divisible by its digit sum 3; a semiprime: 3 × 67, the product of two primes.
- 2
201 is composite. Its prime factorisation is
- 3
The divisors add up to 272; without 201 itself that is 71, so 201 is deficient (71 is less than 201). Euler's totient φ(201) = 132 numbers up to 201 share no factor with it.
- 4
The digits of 201 add up to 3, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 18 steps to reach 1.
LaTeX source of the formulas on this page
\[ 201 = 3 \times 67 \]
201 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 272 |
| Euler totient φ(n) | 132 |
| Square | 40401 |
| Cube | 8120601 |
| Square root | 14.177447 |
| Digit sum / digital root | 3 / 3 |
| Collatz steps to 1 | 18 |
| Scientific notation | 2.01 × |
201 in other forms
| Form | Value |
|---|---|
| In words | two hundred and one |
| Roman numerals | CCI |
| Binary (base 2) | 11001001 |
| Octal (base 8) | 311 |
| Hexadecimal (base 16) | C9 |
| Base 3 | 21110 |
| As time | 201 seconds = 3 min 21 s |
Is 201 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (201 ÷ 3 = 67) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | A number is divisible by 7 if double the last digit and subtract it from the rest: the result is a multiple of 7. |
| 8 | No (remainder 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 201 a prime number?
No. 201 = 3 × 67, so it is divisible by 3.
What are the factors of 201?
1, 3, 67, 201.
What is 201 in binary?
11001001 (hexadecimal C9, octal 311).
What is the square root of 201?
About 14.1774.
What is 201 in Roman numerals?
CCI.
Is 201 divisible by 3?
Yes. Its digits add up to 3, a multiple of 3.
What is special about the number 201?
201 is a Harshad number: divisible by its digit sum 3; a semiprime: 3 × 67, the product of two primes.