The number 84210
84210 is a composite number with 32 divisors. Its prime factorisation is 2 × 3 × 5 × 7 × 401. Divisors (32): 1, 2, 3, 5, 6, 7, 10, 14, 15, 21, 30, 35, 42, 70, 105, 210 … 84210.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 84210: a Harshad number: divisible by its digit sum 15.
- 2
84210 is composite. Its prime factorisation is
- 3
The divisors add up to 231552; without 84210 itself that is 147342, so 84210 is abundant (147342 is more than 84210). Euler's totient φ(84210) = 19200 numbers up to 84210 share no factor with it.
- 4
The digits of 84210 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 120 steps to reach 1.
LaTeX source of the formulas on this page
\[ 84210 = 2 \times 3 \times 5 \times 7 \times 401 \]
84210 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 231552 |
| Euler totient φ(n) | 19200 |
| Square | 7091324100 |
| Cube | 597160402461000 |
| Square root | 290.189593 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 120 |
| Scientific notation | 8.421 × |
84210 in other forms
| Form | Value |
|---|---|
| In words | eighty-four thousand two hundred and ten |
| Binary (base 2) | 10100100011110010 |
| Octal (base 8) | 244362 |
| Hexadecimal (base 16) | 148F2 |
| Base 3 | 11021111220 |
| As time | 84210 seconds = 23 h 23 min 30 s |
Is 84210 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (84210 ÷ 2 = 42105) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (84210 ÷ 3 = 28070) | 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 (84210 ÷ 5 = 16842) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (84210 ÷ 6 = 14035) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (84210 ÷ 7 = 12030) | 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 2) | 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 | Yes (84210 ÷ 10 = 8421) | 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 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 84210 a prime number?
No. 84210 = 2 × 3 × 5 × 7 × 401, so it is divisible by 2.
What are the factors of 84210?
1, 2, 3, 5, 6, 7, 10, 14, 15, 21, 30, 35, 42, 70, 105, 210, 401, 802, 1203, 2005, 2406, 2807, 4010, 5614, 6015, 8421, 12030, 14035, 16842, 28070, 42105, 84210.
What is 84210 in binary?
10100100011110010 (hexadecimal 148F2, octal 244362).
What is the square root of 84210?
About 290.1896.
Is 84210 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 84210?
84210 is a Harshad number: divisible by its digit sum 15.