The number 77644
77644 is a composite number with 24 divisors. Its prime factorisation is × 7 × 47 × 59. Divisors (24): 1, 2, 4, 7, 14, 28, 47, 59, 94, 118, 188, 236, 329, 413, 658, 826 … 77644.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 77644: a Harshad number: divisible by its digit sum 28.
- 2
77644 is composite. Its prime factorisation is
- 3
The divisors add up to 161280; without 77644 itself that is 83636, so 77644 is abundant (83636 is more than 77644). Euler's totient φ(77644) = 32016 numbers up to 77644 share no factor with it.
- 4
The digits of 77644 add up to 28, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 182 steps to reach 1.
LaTeX source of the formulas on this page
\[ 77644 = 2^{2} \times 7 \times 47 \times 59 \]77644 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 161280 |
| Euler totient φ(n) | 32016 |
| Square | 6028590736 |
| Cube | 468083899105984 |
| Square root | 278.646730 (= 2√19411) |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 182 |
| Scientific notation | 7.7644 × |
77644 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand six hundred and forty-four |
| Binary (base 2) | 10010111101001100 |
| Octal (base 8) | 227514 |
| Hexadecimal (base 16) | 12F4C |
| Base 3 | 10221111201 |
| As time | 77644 seconds = 21 h 34 min 4 s |
Is 77644 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (77644 ÷ 2 = 38822) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (77644 ÷ 4 = 19411) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (77644 ÷ 7 = 11092) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 4) | 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 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 77644 a prime number?
No. 77644 = × 7 × 47 × 59, so it is divisible by 2.
What are the factors of 77644?
1, 2, 4, 7, 14, 28, 47, 59, 94, 118, 188, 236, 329, 413, 658, 826, 1316, 1652, 2773, 5546, 11092, 19411, 38822, 77644.
What is 77644 in binary?
10010111101001100 (hexadecimal 12F4C, octal 227514).
What is the square root of 77644?
About 278.6467, exactly 2√19411.
Is 77644 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 77644?
77644 is a Harshad number: divisible by its digit sum 28.