The number 1901
1901 is the 291st prime number. Its only divisors are 1 and 1901.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1901: the 291st prime number.
- 2
1901 is prime, so its only factors are 1 and 1901. It is the 291st prime; the next prime is 1907 and the one before is 1889.
- 3
The divisors add up to 1902; without 1901 itself that is 1, so 1901 is deficient (1 is less than 1901). Euler's totient φ(1901) = 1900 numbers up to 1901 share no factor with it.
- 4
The digits of 1901 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 29 steps to reach 1.
1901 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 1902 |
| Euler totient φ(n) | 1900 |
| Square | 3613801 |
| Cube | 6869835701 |
| Square root | 43.600459 |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 29 |
| Scientific notation | 1.901 × |
1901 in other forms
| Form | Value |
|---|---|
| In words | one thousand nine hundred and one |
| Roman numerals | MCMI |
| Binary (base 2) | 11101101101 |
| Octal (base 8) | 3555 |
| Hexadecimal (base 16) | 76D |
| Base 3 | 2121102 |
| As time | 1901 seconds = 31 min 41 s |
Is 1901 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 | No (remainder 2) | 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 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | 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 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1901 a prime number?
Yes. 1901 is divisible only by 1 and itself.
What are the factors of 1901?
1, 1901.
What is 1901 in binary?
11101101101 (hexadecimal 76D, octal 3555).
What is the square root of 1901?
About 43.6005.
What is 1901 in Roman numerals?
MCMI.
Is 1901 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 1901?
1901 is the 291st prime number.