The number 81473
81473 is a composite number with 8 divisors. Its prime factorisation is 7 × 103 × 113. Divisors (8): 1, 7, 103, 113, 721, 791, 11639, 81473.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 81473: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
81473 is composite. Its prime factorisation is
- 3
The divisors add up to 94848; without 81473 itself that is 13375, so 81473 is deficient (13375 is less than 81473). Euler's totient φ(81473) = 68544 numbers up to 81473 share no factor with it.
- 4
The digits of 81473 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 37 steps to reach 1.
LaTeX source of the formulas on this page
\[ 81473 = 7 \times 103 \times 113 \]
81473 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 94848 |
| Euler totient φ(n) | 68544 |
| Square | 6637849729 |
| Cube | 540805530970817 |
| Square root | 285.434756 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 37 |
| Scientific notation | 8.1473 × |
81473 in other forms
| Form | Value |
|---|---|
| In words | eighty-one thousand four hundred and seventy-three |
| Binary (base 2) | 10011111001000001 |
| Octal (base 8) | 237101 |
| Hexadecimal (base 16) | 13E41 |
| Base 3 | 11010202112 |
| As time | 81473 seconds = 22 h 37 min 53 s |
Is 81473 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 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (81473 ÷ 7 = 11639) | 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 1) | 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 | No (remainder 3) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 81473 a prime number?
No. 81473 = 7 × 103 × 113, so it is divisible by 7.
What are the factors of 81473?
1, 7, 103, 113, 721, 791, 11639, 81473.
What is 81473 in binary?
10011111001000001 (hexadecimal 13E41, octal 237101).
What is the square root of 81473?
About 285.4348.
Is 81473 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 81473?
81473 is a happy number: repeatedly adding the squares of its digits reaches 1.