The number 39729
39729 is a composite number with 16 divisors. Its prime factorisation is 3 × 17 × 19 × 41. Divisors (16): 1, 3, 17, 19, 41, 51, 57, 123, 323, 697, 779, 969, 2091, 2337, 13243, 39729.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
39729 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
39729 is composite. Its prime factorisation is
- 3
The divisors add up to 60480; without 39729 itself that is 20751, so 39729 is deficient (20751 is less than 39729). Euler's totient φ(39729) = 23040 numbers up to 39729 share no factor with it.
- 4
The digits of 39729 add up to 30, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 119 steps to reach 1.
LaTeX source of the formulas on this page
\[ 39729 = 3 \times 17 \times 19 \times 41 \]
39729 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 60480 |
| Euler totient φ(n) | 23040 |
| Square | 1578393441 |
| Cube | 62707993017489 |
| Square root | 199.321349 |
| Digit sum / digital root | 30 / 3 |
| Collatz steps to 1 | 119 |
| Scientific notation | 3.9729 × |
39729 in other forms
| Form | Value |
|---|---|
| In words | thirty-nine thousand seven hundred and twenty-nine |
| Binary (base 2) | 1001101100110001 |
| Octal (base 8) | 115461 |
| Hexadecimal (base 16) | 9B31 |
| Base 3 | 2000111110 |
| As time | 39729 seconds = 11 h 2 min 9 s |
Is 39729 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 (39729 ÷ 3 = 13243) | 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 4) | 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 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 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 9) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | 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 39729 a prime number?
No. 39729 = 3 × 17 × 19 × 41, so it is divisible by 3.
What are the factors of 39729?
1, 3, 17, 19, 41, 51, 57, 123, 323, 697, 779, 969, 2091, 2337, 13243, 39729.
What is 39729 in binary?
1001101100110001 (hexadecimal 9B31, octal 115461).
What is the square root of 39729?
About 199.3213.
Is 39729 divisible by 3?
Yes. Its digits add up to 30, a multiple of 3.
What is special about the number 39729?
It is a composite number with 16 divisors.