The number 72975
72975 is a composite number with 24 divisors. Its prime factorisation is 3 × × 7 × 139. Divisors (24): 1, 3, 5, 7, 15, 21, 25, 35, 75, 105, 139, 175, 417, 525, 695, 973 … 72975.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72975: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
72975 is composite. Its prime factorisation is
- 3
The divisors add up to 138880; without 72975 itself that is 65905, so 72975 is deficient (65905 is less than 72975). Euler's totient φ(72975) = 33120 numbers up to 72975 share no factor with it.
- 4
The digits of 72975 add up to 30, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 68 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72975 = 3 \times 5^{2} \times 7 \times 139 \]72975 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 138880 |
| Euler totient φ(n) | 33120 |
| Square | 5325350625 |
| Cube | 388617461859375 |
| Square root | 270.138853 (= 5√2919) |
| Digit sum / digital root | 30 / 3 |
| Collatz steps to 1 | 68 |
| Scientific notation | 7.2975 × |
72975 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand nine hundred and seventy-five |
| Binary (base 2) | 10001110100001111 |
| Octal (base 8) | 216417 |
| Hexadecimal (base 16) | 11D0F |
| Base 3 | 10201002210 |
| As time | 72975 seconds = 20 h 16 min 15 s |
Is 72975 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 | Yes (72975 ÷ 3 = 24325) | 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 | Yes (72975 ÷ 5 = 14595) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (72975 ÷ 7 = 10425) | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72975 a prime number?
No. 72975 = 3 × × 7 × 139, so it is divisible by 3.
What are the factors of 72975?
1, 3, 5, 7, 15, 21, 25, 35, 75, 105, 139, 175, 417, 525, 695, 973, 2085, 2919, 3475, 4865, 10425, 14595, 24325, 72975.
What is 72975 in binary?
10001110100001111 (hexadecimal 11D0F, octal 216417).
What is the square root of 72975?
About 270.1389, exactly 5√2919.
Is 72975 divisible by 3?
Yes. Its digits add up to 30, a multiple of 3.
What is special about the number 72975?
72975 is a happy number: repeatedly adding the squares of its digits reaches 1.