The number 71631
71631 is a triangular number: 1 + 2 + … + 378 = 71631. Its prime factorisation is × 7 × 379. Divisors (16): 1, 3, 7, 9, 21, 27, 63, 189, 379, 1137, 2653, 3411, 7959, 10233, 23877, 71631.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 71631: a triangular number: 1 + 2 + … + 378 = 71631.
- 2
71631 is composite. Its prime factorisation is
- 3
The divisors add up to 121600; without 71631 itself that is 49969, so 71631 is deficient (49969 is less than 71631). Euler's totient φ(71631) = 40824 numbers up to 71631 share no factor with it.
- 4
The digits of 71631 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 143 steps to reach 1.
LaTeX source of the formulas on this page
\[ 71631 = 3^{3} \times 7 \times 379 \]71631 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 121600 |
| Euler totient φ(n) | 40824 |
| Square | 5131000161 |
| Cube | 367538672532591 |
| Square root | 267.639683 (= 3√7959) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 143 |
| Scientific notation | 7.1631 × |
71631 in other forms
| Form | Value |
|---|---|
| In words | seventy-one thousand six hundred and thirty-one |
| Binary (base 2) | 10001011111001111 |
| Octal (base 8) | 213717 |
| Hexadecimal (base 16) | 117CF |
| Base 3 | 10122021000 |
| As time | 71631 seconds = 19 h 53 min 51 s |
Is 71631 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 (71631 ÷ 3 = 23877) | 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 (71631 ÷ 7 = 10233) | 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 | Yes (71631 ÷ 9 = 7959) | 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 10) | 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 71631 a prime number?
No. 71631 = × 7 × 379, so it is divisible by 3.
What are the factors of 71631?
1, 3, 7, 9, 21, 27, 63, 189, 379, 1137, 2653, 3411, 7959, 10233, 23877, 71631.
What is 71631 in binary?
10001011111001111 (hexadecimal 117CF, octal 213717).
What is the square root of 71631?
About 267.6397, exactly 3√7959.
Is 71631 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 71631?
71631 is a triangular number: 1 + 2 + … + 378 = 71631.