The number 72990
72990 is a composite number with 24 divisors. Its prime factorisation is 2 × × 5 × 811. Divisors (24): 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90, 811, 1622, 2433, 4055 … 72990.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
72990 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
72990 is composite. Its prime factorisation is
- 3
The divisors add up to 190008; without 72990 itself that is 117018, so 72990 is abundant (117018 is more than 72990). Euler's totient φ(72990) = 19440 numbers up to 72990 share no factor with it.
- 4
The digits of 72990 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 187 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72990 = 2 \times 3^{2} \times 5 \times 811 \]72990 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 190008 |
| Euler totient φ(n) | 19440 |
| Square | 5327540100 |
| Cube | 388857151899000 |
| Square root | 270.166615 (= 3√8110) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 187 |
| Scientific notation | 7.299 × |
72990 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand nine hundred and ninety |
| Binary (base 2) | 10001110100011110 |
| Octal (base 8) | 216436 |
| Hexadecimal (base 16) | 11D1E |
| Base 3 | 10201010100 |
| As time | 72990 seconds = 20 h 16 min 30 s |
Is 72990 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (72990 ÷ 2 = 36495) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (72990 ÷ 3 = 24330) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (72990 ÷ 5 = 14598) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (72990 ÷ 6 = 12165) | 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 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (72990 ÷ 9 = 8110) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (72990 ÷ 10 = 7299) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72990 a prime number?
No. 72990 = 2 × × 5 × 811, so it is divisible by 2.
What are the factors of 72990?
1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90, 811, 1622, 2433, 4055, 4866, 7299, 8110, 12165, 14598, 24330, 36495, 72990.
What is 72990 in binary?
10001110100011110 (hexadecimal 11D1E, octal 216436).
What is the square root of 72990?
About 270.1666, exactly 3√8110.
Is 72990 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 72990?
It is a composite number with 24 divisors.