The number 77428
77428 is a composite number with 12 divisors. Its prime factorisation is × 13 × 1489. Divisors (12): 1, 2, 4, 13, 26, 52, 1489, 2978, 5956, 19357, 38714, 77428.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
77428 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
77428 is composite. Its prime factorisation is
- 3
The divisors add up to 146020; without 77428 itself that is 68592, so 77428 is deficient (68592 is less than 77428). Euler's totient φ(77428) = 35712 numbers up to 77428 share no factor with it.
- 4
The digits of 77428 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 169 steps to reach 1.
LaTeX source of the formulas on this page
\[ 77428 = 2^{2} \times 13 \times 1489 \]77428 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 146020 |
| Euler totient φ(n) | 35712 |
| Square | 5995095184 |
| Cube | 464188229906752 |
| Square root | 278.258872 (= 2√19357) |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 169 |
| Scientific notation | 7.7428 × |
77428 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand four hundred and twenty-eight |
| Binary (base 2) | 10010111001110100 |
| Octal (base 8) | 227164 |
| Hexadecimal (base 16) | 12E74 |
| Base 3 | 10221012201 |
| As time | 77428 seconds = 21 h 30 min 28 s |
Is 77428 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (77428 ÷ 2 = 38714) | 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 (77428 ÷ 4 = 19357) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | 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 | No (remainder 1) | 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 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | 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 77428 a prime number?
No. 77428 = × 13 × 1489, so it is divisible by 2.
What are the factors of 77428?
1, 2, 4, 13, 26, 52, 1489, 2978, 5956, 19357, 38714, 77428.
What is 77428 in binary?
10010111001110100 (hexadecimal 12E74, octal 227164).
What is the square root of 77428?
About 278.2589, exactly 2√19357.
Is 77428 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 77428?
It is a composite number with 12 divisors.