The number 77240
77240 is a composite number with 16 divisors. Its prime factorisation is × 5 × 1931. Divisors (16): 1, 2, 4, 5, 8, 10, 20, 40, 1931, 3862, 7724, 9655, 15448, 19310, 38620, 77240.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 77240: a Harshad number: divisible by its digit sum 20.
- 2
77240 is composite. Its prime factorisation is
- 3
The divisors add up to 173880; without 77240 itself that is 96640, so 77240 is abundant (96640 is more than 77240). Euler's totient φ(77240) = 30880 numbers up to 77240 share no factor with it.
- 4
The digits of 77240 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 107 steps to reach 1.
LaTeX source of the formulas on this page
\[ 77240 = 2^{3} \times 5 \times 1931 \]77240 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 173880 |
| Euler totient φ(n) | 30880 |
| Square | 5966017600 |
| Cube | 460815199424000 |
| Square root | 277.920852 (= 2√19310) |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 107 |
| Scientific notation | 7.724 × |
77240 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand two hundred and forty |
| Binary (base 2) | 10010110110111000 |
| Octal (base 8) | 226670 |
| Hexadecimal (base 16) | 12DB8 |
| Base 3 | 10220221202 |
| As time | 77240 seconds = 21 h 27 min 20 s |
Is 77240 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (77240 ÷ 2 = 38620) | 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 (77240 ÷ 4 = 19310) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (77240 ÷ 5 = 15448) | 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 2) | 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 (77240 ÷ 8 = 9655) | 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 (77240 ÷ 10 = 7724) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | 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 77240 a prime number?
No. 77240 = × 5 × 1931, so it is divisible by 2.
What are the factors of 77240?
1, 2, 4, 5, 8, 10, 20, 40, 1931, 3862, 7724, 9655, 15448, 19310, 38620, 77240.
What is 77240 in binary?
10010110110111000 (hexadecimal 12DB8, octal 226670).
What is the square root of 77240?
About 277.9209, exactly 2√19310.
Is 77240 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 77240?
77240 is a Harshad number: divisible by its digit sum 20.