The number 51240
51240 is a composite number with 64 divisors. Its prime factorisation is × 3 × 5 × 7 × 61. Divisors (64): 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 20, 21, 24, 28 … 51240.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 51240: a Harshad number: divisible by its digit sum 12.
- 2
51240 is composite. Its prime factorisation is
- 3
The divisors add up to 178560; without 51240 itself that is 127320, so 51240 is abundant (127320 is more than 51240). Euler's totient φ(51240) = 11520 numbers up to 51240 share no factor with it.
- 4
The digits of 51240 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 65 steps to reach 1.
LaTeX source of the formulas on this page
\[ 51240 = 2^{3} \times 3 \times 5 \times 7 \times 61 \]51240 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 64 |
| Sum of divisors | 178560 |
| Euler totient φ(n) | 11520 |
| Square | 2625537600 |
| Cube | 134532546624000 |
| Square root | 226.362541 (= 2√12810) |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 65 |
| Scientific notation | 5.124 × |
51240 in other forms
| Form | Value |
|---|---|
| In words | fifty-one thousand two hundred and forty |
| Binary (base 2) | 1100100000101000 |
| Octal (base 8) | 144050 |
| Hexadecimal (base 16) | C828 |
| Base 3 | 2121021210 |
| As time | 51240 seconds = 14 h 14 min 0 s |
Is 51240 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (51240 ÷ 2 = 25620) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (51240 ÷ 3 = 17080) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (51240 ÷ 4 = 12810) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (51240 ÷ 5 = 10248) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (51240 ÷ 6 = 8540) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (51240 ÷ 7 = 7320) | 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 (51240 ÷ 8 = 6405) | 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 (51240 ÷ 10 = 5124) | 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 | Yes (51240 ÷ 12 = 4270) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 51240 a prime number?
No. 51240 = × 3 × 5 × 7 × 61, so it is divisible by 2.
What are the factors of 51240?
1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 20, 21, 24, 28, 30, 35, 40, 42, 56, 60, 61, 70, 84, 105, 120, 122, 140, 168, 183, 210, 244, 280, 305, 366, 420, 427, 488, 610, 732, 840, 854, 915, 1220, 1281, 1464, 1708, 1830, 2135, 2440, 2562, 3416, 3660, 4270, 5124, 6405, 7320, 8540, 10248, 12810, 17080, 25620, 51240.
What is 51240 in binary?
1100100000101000 (hexadecimal C828, octal 144050).
What is the square root of 51240?
About 226.3625, exactly 2√12810.
Is 51240 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 51240?
51240 is a Harshad number: divisible by its digit sum 12.