The number 77490
77490 is a composite number with 64 divisors. Its prime factorisation is 2 × × 5 × 7 × 41. Divisors (64): 1, 2, 3, 5, 6, 7, 9, 10, 14, 15, 18, 21, 27, 30, 35, 41 … 77490.
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How to work it out
- 1
What is special about 77490: a Harshad number: divisible by its digit sum 27.
- 2
77490 is composite. Its prime factorisation is
- 3
The divisors add up to 241920; without 77490 itself that is 164430, so 77490 is abundant (164430 is more than 77490). Euler's totient φ(77490) = 17280 numbers up to 77490 share no factor with it.
- 4
The digits of 77490 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 169 steps to reach 1.
LaTeX source of the formulas on this page
\[ 77490 = 2 \times 3^{3} \times 5 \times 7 \times 41 \]77490 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 64 |
| Sum of divisors | 241920 |
| Euler totient φ(n) | 17280 |
| Square | 6004700100 |
| Cube | 465304210749000 |
| Square root | 278.370257 (= 3√8610) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 169 |
| Scientific notation | 7.749 × |
77490 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand four hundred and ninety |
| Binary (base 2) | 10010111010110010 |
| Octal (base 8) | 227262 |
| Hexadecimal (base 16) | 12EB2 |
| Base 3 | 10221022000 |
| As time | 77490 seconds = 21 h 31 min 30 s |
Is 77490 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (77490 ÷ 2 = 38745) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (77490 ÷ 3 = 25830) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (77490 ÷ 5 = 15498) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (77490 ÷ 6 = 12915) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (77490 ÷ 7 = 11070) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (77490 ÷ 9 = 8610) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (77490 ÷ 10 = 7749) | 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 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 77490 a prime number?
No. 77490 = 2 × × 5 × 7 × 41, so it is divisible by 2.
What are the factors of 77490?
1, 2, 3, 5, 6, 7, 9, 10, 14, 15, 18, 21, 27, 30, 35, 41, 42, 45, 54, 63, 70, 82, 90, 105, 123, 126, 135, 189, 205, 210, 246, 270, 287, 315, 369, 378, 410, 574, 615, 630, 738, 861, 945, 1107, 1230, 1435, 1722, 1845, 1890, 2214, 2583, 2870, 3690, 4305, 5166, 5535, 7749, 8610, 11070, 12915, 15498, 25830, 38745, 77490.
What is 77490 in binary?
10010111010110010 (hexadecimal 12EB2, octal 227262).
What is the square root of 77490?
About 278.3703, exactly 3√8610.
Is 77490 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 77490?
77490 is a Harshad number: divisible by its digit sum 27.