The number 81108
81108 is a composite number with 24 divisors. Its prime factorisation is × × 751. Divisors (24): 1, 2, 3, 4, 6, 9, 12, 18, 27, 36, 54, 108, 751, 1502, 2253, 3004 … 81108.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 81108: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.
- 2
81108 is composite. Its prime factorisation is
- 3
The divisors add up to 210560; without 81108 itself that is 129452, so 81108 is abundant (129452 is more than 81108). Euler's totient φ(81108) = 27000 numbers up to 81108 share no factor with it.
- 4
The digits of 81108 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 37 steps to reach 1.
LaTeX source of the formulas on this page
\[ 81108 = 2^{2} \times 3^{3} \times 751 \]81108 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 210560 |
| Euler totient φ(n) | 27000 |
| Square | 6578507664 |
| Cube | 533569599611712 |
| Square root | 284.794663 (= 6√2253) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 37 |
| Scientific notation | 8.1108 × |
81108 in other forms
| Form | Value |
|---|---|
| In words | eighty-one thousand one hundred and eight |
| Binary (base 2) | 10011110011010100 |
| Octal (base 8) | 236324 |
| Hexadecimal (base 16) | 13CD4 |
| Base 3 | 11010021000 |
| As time | 81108 seconds = 22 h 31 min 48 s |
Is 81108 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (81108 ÷ 2 = 40554) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (81108 ÷ 3 = 27036) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (81108 ÷ 4 = 20277) | 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 | Yes (81108 ÷ 6 = 13518) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (81108 ÷ 9 = 9012) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (81108 ÷ 12 = 6759) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 81108 a prime number?
No. 81108 = × × 751, so it is divisible by 2.
What are the factors of 81108?
1, 2, 3, 4, 6, 9, 12, 18, 27, 36, 54, 108, 751, 1502, 2253, 3004, 4506, 6759, 9012, 13518, 20277, 27036, 40554, 81108.
What is 81108 in binary?
10011110011010100 (hexadecimal 13CD4, octal 236324).
What is the square root of 81108?
About 284.7947, exactly 6√2253.
Is 81108 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 81108?
81108 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.