The number 20740
20740 is a composite number with 24 divisors. Its prime factorisation is × 5 × 17 × 61. Divisors (24): 1, 2, 4, 5, 10, 17, 20, 34, 61, 68, 85, 122, 170, 244, 305, 340 … 20740.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
20740 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
20740 is composite. Its prime factorisation is
- 3
The divisors add up to 46872; without 20740 itself that is 26132, so 20740 is abundant (26132 is more than 20740). Euler's totient φ(20740) = 7680 numbers up to 20740 share no factor with it.
- 4
The digits of 20740 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 43 steps to reach 1.
LaTeX source of the formulas on this page
\[ 20740 = 2^{2} \times 5 \times 17 \times 61 \]20740 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 46872 |
| Euler totient φ(n) | 7680 |
| Square | 430147600 |
| Cube | 8921261224000 |
| Square root | 144.013888 (= 2√5185) |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 43 |
| Scientific notation | 2.074 × |
20740 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand seven hundred and forty |
| Binary (base 2) | 101000100000100 |
| Octal (base 8) | 50404 |
| Hexadecimal (base 16) | 5104 |
| Base 3 | 1001110011 |
| As time | 20740 seconds = 5 h 45 min 40 s |
Is 20740 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (20740 ÷ 2 = 10370) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (20740 ÷ 4 = 5185) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (20740 ÷ 5 = 4148) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (20740 ÷ 10 = 2074) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20740 a prime number?
No. 20740 = × 5 × 17 × 61, so it is divisible by 2.
What are the factors of 20740?
1, 2, 4, 5, 10, 17, 20, 34, 61, 68, 85, 122, 170, 244, 305, 340, 610, 1037, 1220, 2074, 4148, 5185, 10370, 20740.
What is 20740 in binary?
101000100000100 (hexadecimal 5104, octal 50404).
What is the square root of 20740?
About 144.0139, exactly 2√5185.
Is 20740 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 20740?
It is a composite number with 24 divisors.