The number 39800
39800 is a composite number with 24 divisors. Its prime factorisation is × × 199. Divisors (24): 1, 2, 4, 5, 8, 10, 20, 25, 40, 50, 100, 199, 200, 398, 796, 995 … 39800.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 39800: a Harshad number: divisible by its digit sum 20.
- 2
39800 is composite. Its prime factorisation is
- 3
The divisors add up to 93000; without 39800 itself that is 53200, so 39800 is abundant (53200 is more than 39800). Euler's totient φ(39800) = 15840 numbers up to 39800 share no factor with it.
- 4
The digits of 39800 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 75 steps to reach 1.
LaTeX source of the formulas on this page
\[ 39800 = 2^{3} \times 5^{2} \times 199 \]39800 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 93000 |
| Euler totient φ(n) | 15840 |
| Square | 1584040000 |
| Cube | 63044792000000 |
| Square root | 199.499373 (= 10√398) |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 75 |
| Scientific notation | 3.98 × |
39800 in other forms
| Form | Value |
|---|---|
| In words | thirty-nine thousand eight hundred |
| Binary (base 2) | 1001101101111000 |
| Octal (base 8) | 115570 |
| Hexadecimal (base 16) | 9B78 |
| Base 3 | 2000121002 |
| As time | 39800 seconds = 11 h 3 min 20 s |
Is 39800 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (39800 ÷ 2 = 19900) | 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 (39800 ÷ 4 = 9950) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (39800 ÷ 5 = 7960) | 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 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 (39800 ÷ 8 = 4975) | 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 | Yes (39800 ÷ 10 = 3980) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 2) | 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 39800 a prime number?
No. 39800 = × × 199, so it is divisible by 2.
What are the factors of 39800?
1, 2, 4, 5, 8, 10, 20, 25, 40, 50, 100, 199, 200, 398, 796, 995, 1592, 1990, 3980, 4975, 7960, 9950, 19900, 39800.
What is 39800 in binary?
1001101101111000 (hexadecimal 9B78, octal 115570).
What is the square root of 39800?
About 199.4994, exactly 10√398.
Is 39800 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 39800?
39800 is a Harshad number: divisible by its digit sum 20.