The number 77642
77642 is a composite number with 4 divisors. Its prime factorisation is 2 × 38821. Divisors (4): 1, 2, 38821, 77642.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 77642: a semiprime: 2 × 38821, the product of two primes.
- 2
77642 is composite. Its prime factorisation is
- 3
The divisors add up to 116466; without 77642 itself that is 38824, so 77642 is deficient (38824 is less than 77642). Euler's totient φ(77642) = 38820 numbers up to 77642 share no factor with it.
- 4
The digits of 77642 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 182 steps to reach 1.
LaTeX source of the formulas on this page
\[ 77642 = 2 \times 38821 \]
77642 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 116466 |
| Euler totient φ(n) | 38820 |
| Square | 6028280164 |
| Cube | 468047728493288 |
| Square root | 278.643141 |
| Digit sum / digital root | 26 / 8 |
| Collatz steps to 1 | 182 |
| Scientific notation | 7.7642 × |
77642 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand six hundred and forty-two |
| Binary (base 2) | 10010111101001010 |
| Octal (base 8) | 227512 |
| Hexadecimal (base 16) | 12F4A |
| Base 3 | 10221111122 |
| As time | 77642 seconds = 21 h 34 min 2 s |
Is 77642 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (77642 ÷ 2 = 38821) | 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 | No (remainder 2) | 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 2) | 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 | No (remainder 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | 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 77642 a prime number?
No. 77642 = 2 × 38821, so it is divisible by 2.
What are the factors of 77642?
1, 2, 38821, 77642.
What is 77642 in binary?
10010111101001010 (hexadecimal 12F4A, octal 227512).
What is the square root of 77642?
About 278.6431.
Is 77642 divisible by 3?
No. Its digits add up to 26, which is not a multiple of 3.
What is special about the number 77642?
77642 is a semiprime: 2 × 38821, the product of two primes.