The number 72440
72440 is a composite number with 16 divisors. Its prime factorisation is × 5 × 1811. Divisors (16): 1, 2, 4, 5, 8, 10, 20, 40, 1811, 3622, 7244, 9055, 14488, 18110, 36220, 72440.
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How to work it out
- 1
72440 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
72440 is composite. Its prime factorisation is
- 3
The divisors add up to 163080; without 72440 itself that is 90640, so 72440 is abundant (90640 is more than 72440). Euler's totient φ(72440) = 28960 numbers up to 72440 share no factor with it.
- 4
The digits of 72440 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 42 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72440 = 2^{3} \times 5 \times 1811 \]72440 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 163080 |
| Euler totient φ(n) | 28960 |
| Square | 5247553600 |
| Cube | 380132782784000 |
| Square root | 269.146800 (= 2√18110) |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 42 |
| Scientific notation | 7.244 × |
72440 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand four hundred and forty |
| Binary (base 2) | 10001101011111000 |
| Octal (base 8) | 215370 |
| Hexadecimal (base 16) | 11AF8 |
| Base 3 | 10200100222 |
| As time | 72440 seconds = 20 h 7 min 20 s |
Is 72440 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (72440 ÷ 2 = 36220) | 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 | Yes (72440 ÷ 4 = 18110) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (72440 ÷ 5 = 14488) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 | Yes (72440 ÷ 8 = 9055) | 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 | Yes (72440 ÷ 10 = 7244) | 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 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72440 a prime number?
No. 72440 = × 5 × 1811, so it is divisible by 2.
What are the factors of 72440?
1, 2, 4, 5, 8, 10, 20, 40, 1811, 3622, 7244, 9055, 14488, 18110, 36220, 72440.
What is 72440 in binary?
10001101011111000 (hexadecimal 11AF8, octal 215370).
What is the square root of 72440?
About 269.1468, exactly 2√18110.
Is 72440 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 72440?
It is a composite number with 16 divisors.