The number 71240
71240 is a composite number with 32 divisors. Its prime factorisation is × 5 × 13 × 137. Divisors (32): 1, 2, 4, 5, 8, 10, 13, 20, 26, 40, 52, 65, 104, 130, 137, 260 … 71240.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 71240: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
71240 is composite. Its prime factorisation is
- 3
The divisors add up to 173880; without 71240 itself that is 102640, so 71240 is abundant (102640 is more than 71240). Euler's totient φ(71240) = 26112 numbers up to 71240 share no factor with it.
- 4
The digits of 71240 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 99 steps to reach 1.
LaTeX source of the formulas on this page
\[ 71240 = 2^{3} \times 5 \times 13 \times 137 \]71240 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 173880 |
| Euler totient φ(n) | 26112 |
| Square | 5075137600 |
| Cube | 361552802624000 |
| Square root | 266.908224 (= 2√17810) |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 99 |
| Scientific notation | 7.124 × |
71240 in other forms
| Form | Value |
|---|---|
| In words | seventy-one thousand two hundred and forty |
| Binary (base 2) | 10001011001001000 |
| Octal (base 8) | 213110 |
| Hexadecimal (base 16) | 11648 |
| Base 3 | 10121201112 |
| As time | 71240 seconds = 19 h 47 min 20 s |
Is 71240 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (71240 ÷ 2 = 35620) | 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 (71240 ÷ 4 = 17810) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (71240 ÷ 5 = 14248) | 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 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 (71240 ÷ 8 = 8905) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (71240 ÷ 10 = 7124) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | 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 71240 a prime number?
No. 71240 = × 5 × 13 × 137, so it is divisible by 2.
What are the factors of 71240?
1, 2, 4, 5, 8, 10, 13, 20, 26, 40, 52, 65, 104, 130, 137, 260, 274, 520, 548, 685, 1096, 1370, 1781, 2740, 3562, 5480, 7124, 8905, 14248, 17810, 35620, 71240.
What is 71240 in binary?
10001011001001000 (hexadecimal 11648, octal 213110).
What is the square root of 71240?
About 266.9082, exactly 2√17810.
Is 71240 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 71240?
71240 is a happy number: repeatedly adding the squares of its digits reaches 1.