The number 72471
72471 is a composite number with 24 divisors. Its prime factorisation is 3 × × 17 × 29. Divisors (24): 1, 3, 7, 17, 21, 29, 49, 51, 87, 119, 147, 203, 357, 493, 609, 833 … 72471.
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How to work it out
- 1
What is special about 72471: a Harshad number: divisible by its digit sum 21.
- 2
72471 is composite. Its prime factorisation is
- 3
The divisors add up to 123120; without 72471 itself that is 50649, so 72471 is deficient (50649 is less than 72471). Euler's totient φ(72471) = 37632 numbers up to 72471 share no factor with it.
- 4
The digits of 72471 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 81 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72471 = 3 \times 7^{2} \times 17 \times 29 \]72471 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 123120 |
| Euler totient φ(n) | 37632 |
| Square | 5252045841 |
| Cube | 380621014143111 |
| Square root | 269.204383 (= 7√1479) |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 81 |
| Scientific notation | 7.2471 × |
72471 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand four hundred and seventy-one |
| Binary (base 2) | 10001101100010111 |
| Octal (base 8) | 215427 |
| Hexadecimal (base 16) | 11B17 |
| Base 3 | 10200102010 |
| As time | 72471 seconds = 20 h 7 min 51 s |
Is 72471 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (72471 ÷ 3 = 24157) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (72471 ÷ 7 = 10353) | 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 | No (remainder 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72471 a prime number?
No. 72471 = 3 × × 17 × 29, so it is divisible by 3.
What are the factors of 72471?
1, 3, 7, 17, 21, 29, 49, 51, 87, 119, 147, 203, 357, 493, 609, 833, 1421, 1479, 2499, 3451, 4263, 10353, 24157, 72471.
What is 72471 in binary?
10001101100010111 (hexadecimal 11B17, octal 215427).
What is the square root of 72471?
About 269.2044, exactly 7√1479.
Is 72471 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 72471?
72471 is a Harshad number: divisible by its digit sum 21.