The number 70720
70720 is a composite number with 56 divisors. Its prime factorisation is × 5 × 13 × 17. Divisors (56): 1, 2, 4, 5, 8, 10, 13, 16, 17, 20, 26, 32, 34, 40, 52, 64 … 70720.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 70720: a Harshad number: divisible by its digit sum 16.
- 2
70720 is composite. Its prime factorisation is
- 3
The divisors add up to 192024; without 70720 itself that is 121304, so 70720 is abundant (121304 is more than 70720). Euler's totient φ(70720) = 24576 numbers up to 70720 share no factor with it.
- 4
The digits of 70720 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 99 steps to reach 1.
LaTeX source of the formulas on this page
\[ 70720 = 2^{6} \times 5 \times 13 \times 17 \]70720 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 56 |
| Sum of divisors | 192024 |
| Euler totient φ(n) | 24576 |
| Square | 5001318400 |
| Cube | 353693237248000 |
| Square root | 265.932322 (= 8√1105) |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 99 |
| Scientific notation | 7.072 × |
70720 in other forms
| Form | Value |
|---|---|
| In words | seventy thousand seven hundred and twenty |
| Binary (base 2) | 10001010001000000 |
| Octal (base 8) | 212100 |
| Hexadecimal (base 16) | 11440 |
| Base 3 | 10121000021 |
| As time | 70720 seconds = 19 h 38 min 40 s |
Is 70720 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (70720 ÷ 2 = 35360) | 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 (70720 ÷ 4 = 17680) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (70720 ÷ 5 = 14144) | 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 | Yes (70720 ÷ 8 = 8840) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (70720 ÷ 10 = 7072) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | 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 70720 a prime number?
No. 70720 = × 5 × 13 × 17, so it is divisible by 2.
What are the factors of 70720?
1, 2, 4, 5, 8, 10, 13, 16, 17, 20, 26, 32, 34, 40, 52, 64, 65, 68, 80, 85, 104, 130, 136, 160, 170, 208, 221, 260, 272, 320, 340, 416, 442, 520, 544, 680, 832, 884, 1040, 1088, 1105, 1360, 1768, 2080, 2210, 2720, 3536, 4160, 4420, 5440, 7072, 8840, 14144, 17680, 35360, 70720.
What is 70720 in binary?
10001010001000000 (hexadecimal 11440, octal 212100).
What is the square root of 70720?
About 265.9323, exactly 8√1105.
Is 70720 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 70720?
70720 is a Harshad number: divisible by its digit sum 16.