The number 19701
19701 is a triangular number: 1 + 2 + … + 198 = 19701. Its prime factorisation is × 11 × 199. Divisors (12): 1, 3, 9, 11, 33, 99, 199, 597, 1791, 2189, 6567, 19701.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 19701: a triangular number: 1 + 2 + … + 198 = 19701.
- 2
19701 is composite. Its prime factorisation is
- 3
The divisors add up to 31200; without 19701 itself that is 11499, so 19701 is deficient (11499 is less than 19701). Euler's totient φ(19701) = 11880 numbers up to 19701 share no factor with it.
- 4
The digits of 19701 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 74 steps to reach 1.
LaTeX source of the formulas on this page
\[ 19701 = 3^{2} \times 11 \times 199 \]19701 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 31200 |
| Euler totient φ(n) | 11880 |
| Square | 388129401 |
| Cube | 7646537329101 |
| Square root | 140.360251 (= 3√2189) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 74 |
| Scientific notation | 1.9701 × |
19701 in other forms
| Form | Value |
|---|---|
| In words | nineteen thousand seven hundred and one |
| Binary (base 2) | 100110011110101 |
| Octal (base 8) | 46365 |
| Hexadecimal (base 16) | 4CF5 |
| Base 3 | 1000000200 |
| As time | 19701 seconds = 5 h 28 min 21 s |
Is 19701 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 (19701 ÷ 3 = 6567) | 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 3) | 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 | Yes (19701 ÷ 9 = 2189) | 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 | Yes (19701 ÷ 11 = 1791) | 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 19701 a prime number?
No. 19701 = × 11 × 199, so it is divisible by 3.
What are the factors of 19701?
1, 3, 9, 11, 33, 99, 199, 597, 1791, 2189, 6567, 19701.
What is 19701 in binary?
100110011110101 (hexadecimal 4CF5, octal 46365).
What is the square root of 19701?
About 140.3603, exactly 3√2189.
Is 19701 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 19701?
19701 is a triangular number: 1 + 2 + … + 198 = 19701.