The number 83721
83721 is a composite number with 16 divisors. Its prime factorisation is 3 × 11 × 43 × 59. Divisors (16): 1, 3, 11, 33, 43, 59, 129, 177, 473, 649, 1419, 1947, 2537, 7611, 27907, 83721.
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How to work it out
- 1
83721 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
83721 is composite. Its prime factorisation is
- 3
The divisors add up to 126720; without 83721 itself that is 42999, so 83721 is deficient (42999 is less than 83721). Euler's totient φ(83721) = 48720 numbers up to 83721 share no factor with it.
- 4
The digits of 83721 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 182 steps to reach 1.
LaTeX source of the formulas on this page
\[ 83721 = 3 \times 11 \times 43 \times 59 \]
83721 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 126720 |
| Euler totient φ(n) | 48720 |
| Square | 7009205841 |
| Cube | 586817722214361 |
| Square root | 289.345814 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 182 |
| Scientific notation | 8.3721 × |
83721 in other forms
| Form | Value |
|---|---|
| In words | eighty-three thousand seven hundred and twenty-one |
| Binary (base 2) | 10100011100001001 |
| Octal (base 8) | 243411 |
| Hexadecimal (base 16) | 14709 |
| Base 3 | 11020211210 |
| As time | 83721 seconds = 23 h 15 min 21 s |
Is 83721 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 (83721 ÷ 3 = 27907) | 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 1) | 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 1) | 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 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (83721 ÷ 11 = 7611) | 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 83721 a prime number?
No. 83721 = 3 × 11 × 43 × 59, so it is divisible by 3.
What are the factors of 83721?
1, 3, 11, 33, 43, 59, 129, 177, 473, 649, 1419, 1947, 2537, 7611, 27907, 83721.
What is 83721 in binary?
10100011100001001 (hexadecimal 14709, octal 243411).
What is the square root of 83721?
About 289.3458.
Is 83721 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 83721?
It is a composite number with 16 divisors.