The number 38720
38720 is a composite number with 42 divisors. Its prime factorisation is × 5 × . Divisors (42): 1, 2, 4, 5, 8, 10, 11, 16, 20, 22, 32, 40, 44, 55, 64, 80 … 38720.
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How to work it out
- 1
What is special about 38720: a Harshad number: divisible by its digit sum 20.
- 2
38720 is composite. Its prime factorisation is
- 3
The divisors add up to 101346; without 38720 itself that is 62626, so 38720 is abundant (62626 is more than 38720). Euler's totient φ(38720) = 14080 numbers up to 38720 share no factor with it.
- 4
The digits of 38720 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 23 steps to reach 1.
LaTeX source of the formulas on this page
\[ 38720 = 2^{6} \times 5 \times 11^{2} \]38720 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 42 |
| Sum of divisors | 101346 |
| Euler totient φ(n) | 14080 |
| Square | 1499238400 |
| Cube | 58050510848000 |
| Square root | 196.773982 (= 88√5) |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 23 |
| Scientific notation | 3.872 × |
38720 in other forms
| Form | Value |
|---|---|
| In words | thirty-eight thousand seven hundred and twenty |
| Binary (base 2) | 1001011101000000 |
| Octal (base 8) | 113500 |
| Hexadecimal (base 16) | 9740 |
| Base 3 | 1222010002 |
| As time | 38720 seconds = 10 h 45 min 20 s |
Is 38720 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (38720 ÷ 2 = 19360) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (38720 ÷ 4 = 9680) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (38720 ÷ 5 = 7744) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 | Yes (38720 ÷ 8 = 4840) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (38720 ÷ 10 = 3872) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (38720 ÷ 11 = 3520) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 38720 a prime number?
No. 38720 = × 5 × , so it is divisible by 2.
What are the factors of 38720?
1, 2, 4, 5, 8, 10, 11, 16, 20, 22, 32, 40, 44, 55, 64, 80, 88, 110, 121, 160, 176, 220, 242, 320, 352, 440, 484, 605, 704, 880, 968, 1210, 1760, 1936, 2420, 3520, 3872, 4840, 7744, 9680, 19360, 38720.
What is 38720 in binary?
1001011101000000 (hexadecimal 9740, octal 113500).
What is the square root of 38720?
About 196.7740, exactly 88√5.
Is 38720 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 38720?
38720 is a Harshad number: divisible by its digit sum 20.