The number 97981
97981 is a composite number with 4 divisors. Its prime factorisation is 13 × 7537. Divisors (4): 1, 13, 7537, 97981.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 97981: a semiprime: 13 × 7537, the product of two primes.
- 2
97981 is composite. Its prime factorisation is
- 3
The divisors add up to 105532; without 97981 itself that is 7551, so 97981 is deficient (7551 is less than 97981). Euler's totient φ(97981) = 90432 numbers up to 97981 share no factor with it.
- 4
The digits of 97981 add up to 34, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 66 steps to reach 1.
LaTeX source of the formulas on this page
\[ 97981 = 13 \times 7537 \]
97981 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 105532 |
| Euler totient φ(n) | 90432 |
| Square | 9600276361 |
| Cube | 940644678127141 |
| Square root | 313.019169 |
| Digit sum / digital root | 34 / 7 |
| Collatz steps to 1 | 66 |
| Scientific notation | 9.7981 × |
97981 in other forms
| Form | Value |
|---|---|
| In words | ninety-seven thousand nine hundred and eighty-one |
| Binary (base 2) | 10111111010111101 |
| Octal (base 8) | 277275 |
| Hexadecimal (base 16) | 17EBD |
| Base 3 | 11222101221 |
| As time | 97981 seconds = 27 h 13 min 1 s |
Is 97981 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 1) | 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 2) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | 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 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 97981 a prime number?
No. 97981 = 13 × 7537, so it is divisible by 13.
What are the factors of 97981?
1, 13, 7537, 97981.
What is 97981 in binary?
10111111010111101 (hexadecimal 17EBD, octal 277275).
What is the square root of 97981?
About 313.0192.
Is 97981 divisible by 3?
No. Its digits add up to 34, which is not a multiple of 3.
What is special about the number 97981?
97981 is a semiprime: 13 × 7537, the product of two primes.