The number 39420
39420 is a composite number with 48 divisors. Its prime factorisation is × × 5 × 73. Divisors (48): 1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 27, 30, 36, 45 … 39420.
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How to work it out
- 1
What is special about 39420: a Harshad number: divisible by its digit sum 18.
- 2
39420 is composite. Its prime factorisation is
- 3
The divisors add up to 124320; without 39420 itself that is 84900, so 39420 is abundant (84900 is more than 39420). Euler's totient φ(39420) = 10368 numbers up to 39420 share no factor with it.
- 4
The digits of 39420 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 98 steps to reach 1.
LaTeX source of the formulas on this page
\[ 39420 = 2^{2} \times 3^{3} \times 5 \times 73 \]39420 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 48 |
| Sum of divisors | 124320 |
| Euler totient φ(n) | 10368 |
| Square | 1553936400 |
| Cube | 61256172888000 |
| Square root | 198.544705 (= 6√1095) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 98 |
| Scientific notation | 3.942 × |
39420 in other forms
| Form | Value |
|---|---|
| In words | thirty-nine thousand four hundred and twenty |
| Binary (base 2) | 1001100111111100 |
| Octal (base 8) | 114774 |
| Hexadecimal (base 16) | 99FC |
| Base 3 | 2000002000 |
| As time | 39420 seconds = 10 h 57 min 0 s |
Is 39420 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (39420 ÷ 2 = 19710) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (39420 ÷ 3 = 13140) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (39420 ÷ 4 = 9855) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (39420 ÷ 5 = 7884) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (39420 ÷ 6 = 6570) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (39420 ÷ 9 = 4380) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (39420 ÷ 10 = 3942) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (39420 ÷ 12 = 3285) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 39420 a prime number?
No. 39420 = × × 5 × 73, so it is divisible by 2.
What are the factors of 39420?
1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 27, 30, 36, 45, 54, 60, 73, 90, 108, 135, 146, 180, 219, 270, 292, 365, 438, 540, 657, 730, 876, 1095, 1314, 1460, 1971, 2190, 2628, 3285, 3942, 4380, 6570, 7884, 9855, 13140, 19710, 39420.
What is 39420 in binary?
1001100111111100 (hexadecimal 99FC, octal 114774).
What is the square root of 39420?
About 198.5447, exactly 6√1095.
Is 39420 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 39420?
39420 is a Harshad number: divisible by its digit sum 18.