The number 77390
77390 is a composite number with 16 divisors. Its prime factorisation is 2 × 5 × 71 × 109. Divisors (16): 1, 2, 5, 10, 71, 109, 142, 218, 355, 545, 710, 1090, 7739, 15478, 38695, 77390.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 77390: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
77390 is composite. Its prime factorisation is
- 3
The divisors add up to 142560; without 77390 itself that is 65170, so 77390 is deficient (65170 is less than 77390). Euler's totient φ(77390) = 30240 numbers up to 77390 share no factor with it.
- 4
The digits of 77390 add up to 26, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 138 steps to reach 1.
LaTeX source of the formulas on this page
\[ 77390 = 2 \times 5 \times 71 \times 109 \]
77390 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 142560 |
| Euler totient φ(n) | 30240 |
| Square | 5989212100 |
| Cube | 463505124419000 |
| Square root | 278.190582 |
| Digit sum / digital root | 26 / 8 |
| Collatz steps to 1 | 138 |
| Scientific notation | 7.739 × |
77390 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand three hundred and ninety |
| Binary (base 2) | 10010111001001110 |
| Octal (base 8) | 227116 |
| Hexadecimal (base 16) | 12E4E |
| Base 3 | 10221011022 |
| As time | 77390 seconds = 21 h 29 min 50 s |
Is 77390 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (77390 ÷ 2 = 38695) | 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 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (77390 ÷ 5 = 15478) | 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 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 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (77390 ÷ 10 = 7739) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 77390 a prime number?
No. 77390 = 2 × 5 × 71 × 109, so it is divisible by 2.
What are the factors of 77390?
1, 2, 5, 10, 71, 109, 142, 218, 355, 545, 710, 1090, 7739, 15478, 38695, 77390.
What is 77390 in binary?
10010111001001110 (hexadecimal 12E4E, octal 227116).
What is the square root of 77390?
About 278.1906.
Is 77390 divisible by 3?
No. Its digits add up to 26, which is not a multiple of 3.
What is special about the number 77390?
77390 is a happy number: repeatedly adding the squares of its digits reaches 1.