The number 91388
91388 is a composite number with 24 divisors. Its prime factorisation is × 11 × 31 × 67. Divisors (24): 1, 2, 4, 11, 22, 31, 44, 62, 67, 124, 134, 268, 341, 682, 737, 1364 … 91388.
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How to work it out
- 1
What is special about 91388: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
91388 is composite. Its prime factorisation is
- 3
The divisors add up to 182784; without 91388 itself that is 91396, so 91388 is abundant (91396 is more than 91388). Euler's totient φ(91388) = 39600 numbers up to 91388 share no factor with it.
- 4
The digits of 91388 add up to 29, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 58 steps to reach 1.
LaTeX source of the formulas on this page
\[ 91388 = 2^{2} \times 11 \times 31 \times 67 \]91388 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 182784 |
| Euler totient φ(n) | 39600 |
| Square | 8351766544 |
| Cube | 763251240923072 |
| Square root | 302.304482 (= 2√22847) |
| Digit sum / digital root | 29 / 2 |
| Collatz steps to 1 | 58 |
| Scientific notation | 9.1388 × |
91388 in other forms
| Form | Value |
|---|---|
| In words | ninety-one thousand three hundred and eighty-eight |
| Binary (base 2) | 10110010011111100 |
| Octal (base 8) | 262374 |
| Hexadecimal (base 16) | 164FC |
| Base 3 | 11122100202 |
| As time | 91388 seconds = 25 h 23 min 8 s |
Is 91388 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (91388 ÷ 2 = 45694) | 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 (91388 ÷ 4 = 22847) | 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 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 | No (remainder 2) | 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 | Yes (91388 ÷ 11 = 8308) | 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 91388 a prime number?
No. 91388 = × 11 × 31 × 67, so it is divisible by 2.
What are the factors of 91388?
1, 2, 4, 11, 22, 31, 44, 62, 67, 124, 134, 268, 341, 682, 737, 1364, 1474, 2077, 2948, 4154, 8308, 22847, 45694, 91388.
What is 91388 in binary?
10110010011111100 (hexadecimal 164FC, octal 262374).
What is the square root of 91388?
About 302.3045, exactly 2√22847.
Is 91388 divisible by 3?
No. Its digits add up to 29, which is not a multiple of 3.
What is special about the number 91388?
91388 is a happy number: repeatedly adding the squares of its digits reaches 1.