The number 51420
51420 is a composite number with 24 divisors. Its prime factorisation is × 3 × 5 × 857. Divisors (24): 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60, 857, 1714, 2571, 3428 … 51420.
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How to work it out
- 1
What is special about 51420: a Harshad number: divisible by its digit sum 12.
- 2
51420 is composite. Its prime factorisation is
- 3
The divisors add up to 144144; without 51420 itself that is 92724, so 51420 is abundant (92724 is more than 51420). Euler's totient φ(51420) = 13696 numbers up to 51420 share no factor with it.
- 4
The digits of 51420 add up to 12, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 78 steps to reach 1.
LaTeX source of the formulas on this page
\[ 51420 = 2^{2} \times 3 \times 5 \times 857 \]51420 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 144144 |
| Euler totient φ(n) | 13696 |
| Square | 2644016400 |
| Cube | 135955323288000 |
| Square root | 226.759785 (= 2√12855) |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 78 |
| Scientific notation | 5.142 × |
51420 in other forms
| Form | Value |
|---|---|
| In words | fifty-one thousand four hundred and twenty |
| Binary (base 2) | 1100100011011100 |
| Octal (base 8) | 144334 |
| Hexadecimal (base 16) | C8DC |
| Base 3 | 2121112110 |
| As time | 51420 seconds = 14 h 17 min 0 s |
Is 51420 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (51420 ÷ 2 = 25710) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (51420 ÷ 3 = 17140) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (51420 ÷ 4 = 12855) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (51420 ÷ 5 = 10284) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (51420 ÷ 6 = 8570) | 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 | No (remainder 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (51420 ÷ 10 = 5142) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (51420 ÷ 12 = 4285) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 51420 a prime number?
No. 51420 = × 3 × 5 × 857, so it is divisible by 2.
What are the factors of 51420?
1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60, 857, 1714, 2571, 3428, 4285, 5142, 8570, 10284, 12855, 17140, 25710, 51420.
What is 51420 in binary?
1100100011011100 (hexadecimal C8DC, octal 144334).
What is the square root of 51420?
About 226.7598, exactly 2√12855.
Is 51420 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 51420?
51420 is a Harshad number: divisible by its digit sum 12.