The number 39920
39920 is a composite number with 20 divisors. Its prime factorisation is × 5 × 499. Divisors (20): 1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 499, 998, 1996, 2495, 3992, 4990 … 39920.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
39920 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
39920 is composite. Its prime factorisation is
- 3
The divisors add up to 93000; without 39920 itself that is 53080, so 39920 is abundant (53080 is more than 39920). Euler's totient φ(39920) = 15936 numbers up to 39920 share no factor with it.
- 4
The digits of 39920 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 75 steps to reach 1.
LaTeX source of the formulas on this page
\[ 39920 = 2^{4} \times 5 \times 499 \]39920 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 20 |
| Sum of divisors | 93000 |
| Euler totient φ(n) | 15936 |
| Square | 1593606400 |
| Cube | 63616767488000 |
| Square root | 199.799900 (= 4√2495) |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 75 |
| Scientific notation | 3.992 × |
39920 in other forms
| Form | Value |
|---|---|
| In words | thirty-nine thousand nine hundred and twenty |
| Binary (base 2) | 1001101111110000 |
| Octal (base 8) | 115760 |
| Hexadecimal (base 16) | 9BF0 |
| Base 3 | 2000202112 |
| As time | 39920 seconds = 11 h 5 min 20 s |
Is 39920 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (39920 ÷ 2 = 19960) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (39920 ÷ 4 = 9980) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (39920 ÷ 5 = 7984) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 (39920 ÷ 8 = 4990) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (39920 ÷ 10 = 3992) | 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 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 39920 a prime number?
No. 39920 = × 5 × 499, so it is divisible by 2.
What are the factors of 39920?
1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 499, 998, 1996, 2495, 3992, 4990, 7984, 9980, 19960, 39920.
What is 39920 in binary?
1001101111110000 (hexadecimal 9BF0, octal 115760).
What is the square root of 39920?
About 199.7999, exactly 4√2495.
Is 39920 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 39920?
It is a composite number with 20 divisors.