The number 72240
72240 is a composite number with 80 divisors. Its prime factorisation is × 3 × 5 × 7 × 43. Divisors (80): 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 16, 20, 21, 24 … 72240.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72240: a Harshad number: divisible by its digit sum 15.
- 2
72240 is composite. Its prime factorisation is
- 3
The divisors add up to 261888; without 72240 itself that is 189648, so 72240 is abundant (189648 is more than 72240). Euler's totient φ(72240) = 16128 numbers up to 72240 share no factor with it.
- 4
The digits of 72240 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 42 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72240 = 2^{4} \times 3 \times 5 \times 7 \times 43 \]72240 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 80 |
| Sum of divisors | 261888 |
| Euler totient φ(n) | 16128 |
| Square | 5218617600 |
| Cube | 376992935424000 |
| Square root | 268.774999 (= 4√4515) |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 42 |
| Scientific notation | 7.224 × |
72240 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand two hundred and forty |
| Binary (base 2) | 10001101000110000 |
| Octal (base 8) | 215060 |
| Hexadecimal (base 16) | 11A30 |
| Base 3 | 10200002120 |
| As time | 72240 seconds = 20 h 4 min 0 s |
Is 72240 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (72240 ÷ 2 = 36120) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (72240 ÷ 3 = 24080) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (72240 ÷ 4 = 18060) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (72240 ÷ 5 = 14448) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (72240 ÷ 6 = 12040) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (72240 ÷ 7 = 10320) | 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 (72240 ÷ 8 = 9030) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (72240 ÷ 10 = 7224) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (72240 ÷ 12 = 6020) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72240 a prime number?
No. 72240 = × 3 × 5 × 7 × 43, so it is divisible by 2.
What are the factors of 72240?
1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 16, 20, 21, 24, 28, 30, 35, 40, 42, 43, 48, 56, 60, 70, 80, 84, 86, 105, 112, 120, 129, 140, 168, 172, 210, 215, 240, 258, 280, 301, 336, 344, 420, 430, 516, 560, 602, 645, 688, 840, 860, 903, 1032, 1204, 1290, 1505, 1680, 1720, 1806, 2064, 2408, 2580, 3010, 3440, 3612, 4515, 4816, 5160, 6020, 7224, 9030, 10320, 12040, 14448, 18060, 24080, 36120, 72240.
What is 72240 in binary?
10001101000110000 (hexadecimal 11A30, octal 215060).
What is the square root of 72240?
About 268.7750, exactly 4√4515.
Is 72240 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 72240?
72240 is a Harshad number: divisible by its digit sum 15.