The number 87390
87390 is a composite number with 24 divisors. Its prime factorisation is 2 × × 5 × 971. Divisors (24): 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90, 971, 1942, 2913, 4855 … 87390.
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How to work it out
- 1
What is special about 87390: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
87390 is composite. Its prime factorisation is
- 3
The divisors add up to 227448; without 87390 itself that is 140058, so 87390 is abundant (140058 is more than 87390). Euler's totient φ(87390) = 23280 numbers up to 87390 share no factor with it.
- 4
The digits of 87390 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 102 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87390 = 2 \times 3^{2} \times 5 \times 971 \]87390 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 227448 |
| Euler totient φ(n) | 23280 |
| Square | 7637012100 |
| Cube | 667398487419000 |
| Square root | 295.617997 (= 3√9710) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 102 |
| Scientific notation | 8.739 × |
87390 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand three hundred and ninety |
| Binary (base 2) | 10101010101011110 |
| Octal (base 8) | 252536 |
| Hexadecimal (base 16) | 1555E |
| Base 3 | 11102212200 |
| As time | 87390 seconds = 24 h 16 min 30 s |
Is 87390 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (87390 ÷ 2 = 43695) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (87390 ÷ 3 = 29130) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (87390 ÷ 5 = 17478) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (87390 ÷ 6 = 14565) | 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 | No (remainder 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (87390 ÷ 9 = 9710) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (87390 ÷ 10 = 8739) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87390 a prime number?
No. 87390 = 2 × × 5 × 971, so it is divisible by 2.
What are the factors of 87390?
1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90, 971, 1942, 2913, 4855, 5826, 8739, 9710, 14565, 17478, 29130, 43695, 87390.
What is 87390 in binary?
10101010101011110 (hexadecimal 1555E, octal 252536).
What is the square root of 87390?
About 295.6180, exactly 3√9710.
Is 87390 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 87390?
87390 is a happy number: repeatedly adding the squares of its digits reaches 1.