The number 39872
39872 is a composite number with 28 divisors. Its prime factorisation is × 7 × 89. Divisors (28): 1, 2, 4, 7, 8, 14, 16, 28, 32, 56, 64, 89, 112, 178, 224, 356 … 39872.
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How to work it out
- 1
39872 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
39872 is composite. Its prime factorisation is
- 3
The divisors add up to 91440; without 39872 itself that is 51568, so 39872 is abundant (51568 is more than 39872). Euler's totient φ(39872) = 16896 numbers up to 39872 share no factor with it.
- 4
The digits of 39872 add up to 29, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 137 steps to reach 1.
LaTeX source of the formulas on this page
\[ 39872 = 2^{6} \times 7 \times 89 \]39872 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 28 |
| Sum of divisors | 91440 |
| Euler totient φ(n) | 16896 |
| Square | 1589776384 |
| Cube | 63387563982848 |
| Square root | 199.679744 (= 8√623) |
| Digit sum / digital root | 29 / 2 |
| Collatz steps to 1 | 137 |
| Scientific notation | 3.9872 × |
39872 in other forms
| Form | Value |
|---|---|
| In words | thirty-nine thousand eight hundred and seventy-two |
| Binary (base 2) | 1001101111000000 |
| Octal (base 8) | 115700 |
| Hexadecimal (base 16) | 9BC0 |
| Base 3 | 2000200202 |
| As time | 39872 seconds = 11 h 4 min 32 s |
Is 39872 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (39872 ÷ 2 = 19936) | 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 (39872 ÷ 4 = 9968) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | 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 | Yes (39872 ÷ 7 = 5696) | 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 (39872 ÷ 8 = 4984) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | 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 39872 a prime number?
No. 39872 = × 7 × 89, so it is divisible by 2.
What are the factors of 39872?
1, 2, 4, 7, 8, 14, 16, 28, 32, 56, 64, 89, 112, 178, 224, 356, 448, 623, 712, 1246, 1424, 2492, 2848, 4984, 5696, 9968, 19936, 39872.
What is 39872 in binary?
1001101111000000 (hexadecimal 9BC0, octal 115700).
What is the square root of 39872?
About 199.6797, exactly 8√623.
Is 39872 divisible by 3?
No. Its digits add up to 29, which is not a multiple of 3.
What is special about the number 39872?
It is a composite number with 28 divisors.