The number 20742
20742 is a composite number with 8 divisors. Its prime factorisation is 2 × 3 × 3457. Divisors (8): 1, 2, 3, 6, 3457, 6914, 10371, 20742.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
20742 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
20742 is composite. Its prime factorisation is
- 3
The divisors add up to 41496; without 20742 itself that is 20754, so 20742 is abundant (20754 is more than 20742). Euler's totient φ(20742) = 6912 numbers up to 20742 share no factor with it.
- 4
The digits of 20742 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 43 steps to reach 1.
LaTeX source of the formulas on this page
\[ 20742 = 2 \times 3 \times 3457 \]
20742 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 41496 |
| Euler totient φ(n) | 6912 |
| Square | 430230564 |
| Cube | 8923842358488 |
| Square root | 144.020832 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 43 |
| Scientific notation | 2.0742 × |
20742 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand seven hundred and forty-two |
| Binary (base 2) | 101000100000110 |
| Octal (base 8) | 50406 |
| Hexadecimal (base 16) | 5106 |
| Base 3 | 1001110020 |
| As time | 20742 seconds = 5 h 45 min 42 s |
Is 20742 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (20742 ÷ 2 = 10371) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (20742 ÷ 3 = 6914) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (20742 ÷ 6 = 3457) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20742 a prime number?
No. 20742 = 2 × 3 × 3457, so it is divisible by 2.
What are the factors of 20742?
1, 2, 3, 6, 3457, 6914, 10371, 20742.
What is 20742 in binary?
101000100000110 (hexadecimal 5106, octal 50406).
What is the square root of 20742?
About 144.0208.
Is 20742 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 20742?
It is a composite number with 8 divisors.