The number 75990
75990 is a composite number with 32 divisors. Its prime factorisation is 2 × 3 × 5 × 17 × 149. Divisors (32): 1, 2, 3, 5, 6, 10, 15, 17, 30, 34, 51, 85, 102, 149, 170, 255 … 75990.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 75990: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 30.
- 2
75990 is composite. Its prime factorisation is
- 3
The divisors add up to 194400; without 75990 itself that is 118410, so 75990 is abundant (118410 is more than 75990). Euler's totient φ(75990) = 18944 numbers up to 75990 share no factor with it.
- 4
The digits of 75990 add up to 30, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 63 steps to reach 1.
LaTeX source of the formulas on this page
\[ 75990 = 2 \times 3 \times 5 \times 17 \times 149 \]
75990 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 194400 |
| Euler totient φ(n) | 18944 |
| Square | 5774480100 |
| Cube | 438802742799000 |
| Square root | 275.662838 |
| Digit sum / digital root | 30 / 3 |
| Collatz steps to 1 | 63 |
| Scientific notation | 7.599 × |
75990 in other forms
| Form | Value |
|---|---|
| In words | seventy-five thousand nine hundred and ninety |
| Binary (base 2) | 10010100011010110 |
| Octal (base 8) | 224326 |
| Hexadecimal (base 16) | 128D6 |
| Base 3 | 10212020110 |
| As time | 75990 seconds = 21 h 6 min 30 s |
Is 75990 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (75990 ÷ 2 = 37995) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (75990 ÷ 3 = 25330) | 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 (75990 ÷ 5 = 15198) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (75990 ÷ 6 = 12665) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (75990 ÷ 10 = 7599) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 2) | 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 75990 a prime number?
No. 75990 = 2 × 3 × 5 × 17 × 149, so it is divisible by 2.
What are the factors of 75990?
1, 2, 3, 5, 6, 10, 15, 17, 30, 34, 51, 85, 102, 149, 170, 255, 298, 447, 510, 745, 894, 1490, 2235, 2533, 4470, 5066, 7599, 12665, 15198, 25330, 37995, 75990.
What is 75990 in binary?
10010100011010110 (hexadecimal 128D6, octal 224326).
What is the square root of 75990?
About 275.6628.
Is 75990 divisible by 3?
Yes. Its digits add up to 30, a multiple of 3.
What is special about the number 75990?
75990 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 30.