The number 20724
20724 is a composite number with 24 divisors. Its prime factorisation is × 3 × 11 × 157. Divisors (24): 1, 2, 3, 4, 6, 11, 12, 22, 33, 44, 66, 132, 157, 314, 471, 628 … 20724.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
20724 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
20724 is composite. Its prime factorisation is
- 3
The divisors add up to 53088; without 20724 itself that is 32364, so 20724 is abundant (32364 is more than 20724). Euler's totient φ(20724) = 6240 numbers up to 20724 share no factor with it.
- 4
The digits of 20724 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
\[ 20724 = 2^{2} \times 3 \times 11 \times 157 \]20724 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 53088 |
| Euler totient φ(n) | 6240 |
| Square | 429484176 |
| Cube | 8900630063424 |
| Square root | 143.958327 (= 2√5181) |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 43 |
| Scientific notation | 2.0724 × |
20724 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand seven hundred and twenty-four |
| Binary (base 2) | 101000011110100 |
| Octal (base 8) | 50364 |
| Hexadecimal (base 16) | 50F4 |
| Base 3 | 1001102120 |
| As time | 20724 seconds = 5 h 45 min 24 s |
Is 20724 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (20724 ÷ 2 = 10362) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (20724 ÷ 3 = 6908) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (20724 ÷ 4 = 5181) | 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 | Yes (20724 ÷ 6 = 3454) | 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 4) | 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 4) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (20724 ÷ 11 = 1884) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (20724 ÷ 12 = 1727) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20724 a prime number?
No. 20724 = × 3 × 11 × 157, so it is divisible by 2.
What are the factors of 20724?
1, 2, 3, 4, 6, 11, 12, 22, 33, 44, 66, 132, 157, 314, 471, 628, 942, 1727, 1884, 3454, 5181, 6908, 10362, 20724.
What is 20724 in binary?
101000011110100 (hexadecimal 50F4, octal 50364).
What is the square root of 20724?
About 143.9583, exactly 2√5181.
Is 20724 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 20724?
It is a composite number with 24 divisors.