The number 72989
72989 is a composite number with 4 divisors. Its prime factorisation is 7 × 10427. Divisors (4): 1, 7, 10427, 72989.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72989: a semiprime: 7 × 10427, the product of two primes.
- 2
72989 is composite. Its prime factorisation is
- 3
The divisors add up to 83424; without 72989 itself that is 10435, so 72989 is deficient (10435 is less than 72989). Euler's totient φ(72989) = 62556 numbers up to 72989 share no factor with it.
- 4
The digits of 72989 add up to 35, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 187 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72989 = 7 \times 10427 \]
72989 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 83424 |
| Euler totient φ(n) | 62556 |
| Square | 5327394121 |
| Cube | 388841169497669 |
| Square root | 270.164765 |
| Digit sum / digital root | 35 / 8 |
| Collatz steps to 1 | 187 |
| Scientific notation | 7.2989 × |
72989 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand nine hundred and eighty-nine |
| Binary (base 2) | 10001110100011101 |
| Octal (base 8) | 216435 |
| Hexadecimal (base 16) | 11D1D |
| Base 3 | 10201010022 |
| As time | 72989 seconds = 20 h 16 min 29 s |
Is 72989 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 2) | 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 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (72989 ÷ 7 = 10427) | 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 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 9) | 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 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72989 a prime number?
No. 72989 = 7 × 10427, so it is divisible by 7.
What are the factors of 72989?
1, 7, 10427, 72989.
What is 72989 in binary?
10001110100011101 (hexadecimal 11D1D, octal 216435).
What is the square root of 72989?
About 270.1648.
Is 72989 divisible by 3?
No. Its digits add up to 35, which is not a multiple of 3.
What is special about the number 72989?
72989 is a semiprime: 7 × 10427, the product of two primes.