The number 71520
71520 is a composite number with 48 divisors. Its prime factorisation is × 3 × 5 × 149. Divisors (48): 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40 … 71520.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 71520: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 15.
- 2
71520 is composite. Its prime factorisation is
- 3
The divisors add up to 226800; without 71520 itself that is 155280, so 71520 is abundant (155280 is more than 71520). Euler's totient φ(71520) = 18944 numbers up to 71520 share no factor with it.
- 4
The digits of 71520 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 50 steps to reach 1.
LaTeX source of the formulas on this page
\[ 71520 = 2^{5} \times 3 \times 5 \times 149 \]71520 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 48 |
| Sum of divisors | 226800 |
| Euler totient φ(n) | 18944 |
| Square | 5115110400 |
| Cube | 365832695808000 |
| Square root | 267.432234 (= 4√4470) |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 50 |
| Scientific notation | 7.152 × |
71520 in other forms
| Form | Value |
|---|---|
| In words | seventy-one thousand five hundred and twenty |
| Binary (base 2) | 10001011101100000 |
| Octal (base 8) | 213540 |
| Hexadecimal (base 16) | 11760 |
| Base 3 | 10122002220 |
| As time | 71520 seconds = 19 h 52 min 0 s |
Is 71520 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (71520 ÷ 2 = 35760) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (71520 ÷ 3 = 23840) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (71520 ÷ 4 = 17880) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (71520 ÷ 5 = 14304) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (71520 ÷ 6 = 11920) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 (71520 ÷ 8 = 8940) | 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 (71520 ÷ 10 = 7152) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (71520 ÷ 12 = 5960) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 71520 a prime number?
No. 71520 = × 3 × 5 × 149, so it is divisible by 2.
What are the factors of 71520?
1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 80, 96, 120, 149, 160, 240, 298, 447, 480, 596, 745, 894, 1192, 1490, 1788, 2235, 2384, 2980, 3576, 4470, 4768, 5960, 7152, 8940, 11920, 14304, 17880, 23840, 35760, 71520.
What is 71520 in binary?
10001011101100000 (hexadecimal 11760, octal 213540).
What is the square root of 71520?
About 267.4322, exactly 4√4470.
Is 71520 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 71520?
71520 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 15.