The number 77131
77131 is a composite number with 4 divisors. Its prime factorisation is 137 × 563. Divisors (4): 1, 137, 563, 77131.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 77131: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 137 × 563, the product of two primes.
- 2
77131 is composite. Its prime factorisation is
- 3
The divisors add up to 77832; without 77131 itself that is 701, so 77131 is deficient (701 is less than 77131). Euler's totient φ(77131) = 76432 numbers up to 77131 share no factor with it.
- 4
The digits of 77131 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 76 steps to reach 1.
LaTeX source of the formulas on this page
\[ 77131 = 137 \times 563 \]
77131 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 77832 |
| Euler totient φ(n) | 76432 |
| Square | 5949191161 |
| Cube | 458867063439091 |
| Square root | 277.724684 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 76 |
| Scientific notation | 7.7131 × |
77131 in other forms
| Form | Value |
|---|---|
| In words | seventy-seven thousand one hundred and thirty-one |
| Binary (base 2) | 10010110101001011 |
| Octal (base 8) | 226513 |
| Hexadecimal (base 16) | 12D4B |
| Base 3 | 10220210201 |
| As time | 77131 seconds = 21 h 25 min 31 s |
Is 77131 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | 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 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | 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 3) | 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 1) | 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 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 77131 a prime number?
No. 77131 = 137 × 563, so it is divisible by 137.
What are the factors of 77131?
1, 137, 563, 77131.
What is 77131 in binary?
10010110101001011 (hexadecimal 12D4B, octal 226513).
What is the square root of 77131?
About 277.7247.
Is 77131 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 77131?
77131 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 137 × 563, the product of two primes.