The number 20739
20739 is a composite number with 8 divisors. Its prime factorisation is 3 × 31 × 223. Divisors (8): 1, 3, 31, 93, 223, 669, 6913, 20739.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
20739 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
20739 is composite. Its prime factorisation is
- 3
The divisors add up to 28672; without 20739 itself that is 7933, so 20739 is deficient (7933 is less than 20739). Euler's totient φ(20739) = 13320 numbers up to 20739 share no factor with it.
- 4
The digits of 20739 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 87 steps to reach 1.
LaTeX source of the formulas on this page
\[ 20739 = 3 \times 31 \times 223 \]
20739 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 28672 |
| Euler totient φ(n) | 13320 |
| Square | 430106121 |
| Cube | 8919970843419 |
| Square root | 144.010416 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 87 |
| Scientific notation | 2.0739 × |
20739 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand seven hundred and thirty-nine |
| Binary (base 2) | 101000100000011 |
| Octal (base 8) | 50403 |
| Hexadecimal (base 16) | 5103 |
| Base 3 | 1001110010 |
| As time | 20739 seconds = 5 h 45 min 39 s |
Is 20739 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 (20739 ÷ 3 = 6913) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | 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 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 3) | 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 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20739 a prime number?
No. 20739 = 3 × 31 × 223, so it is divisible by 3.
What are the factors of 20739?
1, 3, 31, 93, 223, 669, 6913, 20739.
What is 20739 in binary?
101000100000011 (hexadecimal 5103, octal 50403).
What is the square root of 20739?
About 144.0104.
Is 20739 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 20739?
It is a composite number with 8 divisors.