The number 75021
75021 is a composite number with 8 divisors. Its prime factorisation is 3 × 17 × 1471. Divisors (8): 1, 3, 17, 51, 1471, 4413, 25007, 75021.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 75021: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
75021 is composite. Its prime factorisation is
- 3
The divisors add up to 105984; without 75021 itself that is 30963, so 75021 is deficient (30963 is less than 75021). Euler's totient φ(75021) = 47040 numbers up to 75021 share no factor with it.
- 4
The digits of 75021 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 112 steps to reach 1.
LaTeX source of the formulas on this page
\[ 75021 = 3 \times 17 \times 1471 \]
75021 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 105984 |
| Euler totient φ(n) | 47040 |
| Square | 5628150441 |
| Cube | 422229474234261 |
| Square root | 273.899617 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 112 |
| Scientific notation | 7.5021 × |
75021 in other forms
| Form | Value |
|---|---|
| In words | seventy-five thousand and twenty-one |
| Binary (base 2) | 10010010100001101 |
| Octal (base 8) | 222415 |
| Hexadecimal (base 16) | 1250D |
| Base 3 | 10210220120 |
| As time | 75021 seconds = 20 h 50 min 21 s |
Is 75021 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (75021 ÷ 3 = 25007) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | 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 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 75021 a prime number?
No. 75021 = 3 × 17 × 1471, so it is divisible by 3.
What are the factors of 75021?
1, 3, 17, 51, 1471, 4413, 25007, 75021.
What is 75021 in binary?
10010010100001101 (hexadecimal 1250D, octal 222415).
What is the square root of 75021?
About 273.8996.
Is 75021 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 75021?
75021 is a happy number: repeatedly adding the squares of its digits reaches 1.