The number 82621
82621 is a triangular number: 1 + 2 + … + 406 = 82621. Its prime factorisation is 7 × 11 × 29 × 37. Divisors (16): 1, 7, 11, 29, 37, 77, 203, 259, 319, 407, 1073, 2233, 2849, 7511, 11803, 82621.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 82621: a triangular number: 1 + 2 + … + 406 = 82621; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
82621 is composite. Its prime factorisation is
- 3
The divisors add up to 109440; without 82621 itself that is 26819, so 82621 is deficient (26819 is less than 82621). Euler's totient φ(82621) = 60480 numbers up to 82621 share no factor with it.
- 4
The digits of 82621 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 151 steps to reach 1.
LaTeX source of the formulas on this page
\[ 82621 = 7 \times 11 \times 29 \times 37 \]
82621 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 109440 |
| Euler totient φ(n) | 60480 |
| Square | 6826229641 |
| Cube | 563989919169061 |
| Square root | 287.438689 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 151 |
| Scientific notation | 8.2621 × |
82621 in other forms
| Form | Value |
|---|---|
| In words | eighty-two thousand six hundred and twenty-one |
| Binary (base 2) | 10100001010111101 |
| Octal (base 8) | 241275 |
| Hexadecimal (base 16) | 142BD |
| Base 3 | 11012100001 |
| As time | 82621 seconds = 22 h 57 min 1 s |
Is 82621 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 | No (remainder 1) | 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 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (82621 ÷ 7 = 11803) | 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 1) | 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 | Yes (82621 ÷ 11 = 7511) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 82621 a prime number?
No. 82621 = 7 × 11 × 29 × 37, so it is divisible by 7.
What are the factors of 82621?
1, 7, 11, 29, 37, 77, 203, 259, 319, 407, 1073, 2233, 2849, 7511, 11803, 82621.
What is 82621 in binary?
10100001010111101 (hexadecimal 142BD, octal 241275).
What is the square root of 82621?
About 287.4387.
Is 82621 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 82621?
82621 is a triangular number: 1 + 2 + … + 406 = 82621; a happy number: repeatedly adding the squares of its digits reaches 1.