The number 16840
16840 is a composite number with 16 divisors. Its prime factorisation is × 5 × 421. Divisors (16): 1, 2, 4, 5, 8, 10, 20, 40, 421, 842, 1684, 2105, 3368, 4210, 8420, 16840.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
16840 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
16840 is composite. Its prime factorisation is
- 3
The divisors add up to 37980; without 16840 itself that is 21140, so 16840 is abundant (21140 is more than 16840). Euler's totient φ(16840) = 6720 numbers up to 16840 share no factor with it.
- 4
The digits of 16840 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 128 steps to reach 1.
LaTeX source of the formulas on this page
\[ 16840 = 2^{3} \times 5 \times 421 \]16840 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 37980 |
| Euler totient φ(n) | 6720 |
| Square | 283585600 |
| Cube | 4775581504000 |
| Square root | 129.769026 (= 2√4210) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 128 |
| Scientific notation | 1.684 × |
16840 in other forms
| Form | Value |
|---|---|
| In words | sixteen thousand eight hundred and forty |
| Binary (base 2) | 100000111001000 |
| Octal (base 8) | 40710 |
| Hexadecimal (base 16) | 41C8 |
| Base 3 | 212002201 |
| As time | 16840 seconds = 4 h 40 min 40 s |
Is 16840 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (16840 ÷ 2 = 8420) | 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 | Yes (16840 ÷ 4 = 4210) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (16840 ÷ 5 = 3368) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | 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 | Yes (16840 ÷ 8 = 2105) | 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 | Yes (16840 ÷ 10 = 1684) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 16840 a prime number?
No. 16840 = × 5 × 421, so it is divisible by 2.
What are the factors of 16840?
1, 2, 4, 5, 8, 10, 20, 40, 421, 842, 1684, 2105, 3368, 4210, 8420, 16840.
What is 16840 in binary?
100000111001000 (hexadecimal 41C8, octal 40710).
What is the square root of 16840?
About 129.7690, exactly 2√4210.
Is 16840 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 16840?
It is a composite number with 16 divisors.