The number 6720
6720 is a composite number with 56 divisors. Its prime factorisation is × 3 × 5 × 7. Divisors (56): 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 16, 20, 21, 24 … 6720.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 6720: a Harshad number: divisible by its digit sum 15.
- 2
6720 is composite. Its prime factorisation is
- 3
The divisors add up to 24384; without 6720 itself that is 17664, so 6720 is abundant (17664 is more than 6720). Euler's totient φ(6720) = 1536 numbers up to 6720 share no factor with it.
- 4
The digits of 6720 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 44 steps to reach 1.
LaTeX source of the formulas on this page
\[ 6720 = 2^{6} \times 3 \times 5 \times 7 \]6720 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 56 |
| Sum of divisors | 24384 |
| Euler totient φ(n) | 1536 |
| Square | 45158400 |
| Cube | 303464448000 |
| Square root | 81.975606 (= 8√105) |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 44 |
| Scientific notation | 6.72 × |
6720 in other forms
| Form | Value |
|---|---|
| In words | six thousand seven hundred and twenty |
| Binary (base 2) | 1101001000000 |
| Octal (base 8) | 15100 |
| Hexadecimal (base 16) | 1A40 |
| Base 3 | 100012220 |
| As time | 6720 seconds = 1 h 52 min 0 s |
Is 6720 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (6720 ÷ 2 = 3360) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (6720 ÷ 3 = 2240) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (6720 ÷ 4 = 1680) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (6720 ÷ 5 = 1344) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (6720 ÷ 6 = 1120) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (6720 ÷ 7 = 960) | 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 (6720 ÷ 8 = 840) | 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 | Yes (6720 ÷ 10 = 672) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (6720 ÷ 12 = 560) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 6720 a prime number?
No. 6720 = × 3 × 5 × 7, so it is divisible by 2.
What are the factors of 6720?
1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 16, 20, 21, 24, 28, 30, 32, 35, 40, 42, 48, 56, 60, 64, 70, 80, 84, 96, 105, 112, 120, 140, 160, 168, 192, 210, 224, 240, 280, 320, 336, 420, 448, 480, 560, 672, 840, 960, 1120, 1344, 1680, 2240, 3360, 6720.
What is 6720 in binary?
1101001000000 (hexadecimal 1A40, octal 15100).
What is the square root of 6720?
About 81.9756, exactly 8√105.
Is 6720 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 6720?
6720 is a Harshad number: divisible by its digit sum 15.