The number 81104
81104 is a composite number with 20 divisors. Its prime factorisation is × 37 × 137. Divisors (20): 1, 2, 4, 8, 16, 37, 74, 137, 148, 274, 296, 548, 592, 1096, 2192, 5069 … 81104.
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How to work it out
- 1
What is special about 81104: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
81104 is composite. Its prime factorisation is
- 3
The divisors add up to 162564; without 81104 itself that is 81460, so 81104 is abundant (81460 is more than 81104). Euler's totient φ(81104) = 39168 numbers up to 81104 share no factor with it.
- 4
The digits of 81104 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 37 steps to reach 1.
LaTeX source of the formulas on this page
\[ 81104 = 2^{4} \times 37 \times 137 \]81104 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 20 |
| Sum of divisors | 162564 |
| Euler totient φ(n) | 39168 |
| Square | 6577858816 |
| Cube | 533490661412864 |
| Square root | 284.787640 (= 4√5069) |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 37 |
| Scientific notation | 8.1104 × |
81104 in other forms
| Form | Value |
|---|---|
| In words | eighty-one thousand one hundred and four |
| Binary (base 2) | 10011110011010000 |
| Octal (base 8) | 236320 |
| Hexadecimal (base 16) | 13CD0 |
| Base 3 | 11010020212 |
| As time | 81104 seconds = 22 h 31 min 44 s |
Is 81104 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (81104 ÷ 2 = 40552) | 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 (81104 ÷ 4 = 20276) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | 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 2) | 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 (81104 ÷ 8 = 10138) | 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 4) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | 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 81104 a prime number?
No. 81104 = × 37 × 137, so it is divisible by 2.
What are the factors of 81104?
1, 2, 4, 8, 16, 37, 74, 137, 148, 274, 296, 548, 592, 1096, 2192, 5069, 10138, 20276, 40552, 81104.
What is 81104 in binary?
10011110011010000 (hexadecimal 13CD0, octal 236320).
What is the square root of 81104?
About 284.7876, exactly 4√5069.
Is 81104 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 81104?
81104 is a happy number: repeatedly adding the squares of its digits reaches 1.