The number 71220
71220 is a composite number with 24 divisors. Its prime factorisation is × 3 × 5 × 1187. Divisors (24): 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60, 1187, 2374, 3561, 4748 … 71220.
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How to work it out
- 1
What is special about 71220: a Harshad number: divisible by its digit sum 12.
- 2
71220 is composite. Its prime factorisation is
- 3
The divisors add up to 199584; without 71220 itself that is 128364, so 71220 is abundant (128364 is more than 71220). Euler's totient φ(71220) = 18976 numbers up to 71220 share no factor with it.
- 4
The digits of 71220 add up to 12, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 143 steps to reach 1.
LaTeX source of the formulas on this page
\[ 71220 = 2^{2} \times 3 \times 5 \times 1187 \]71220 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 199584 |
| Euler totient φ(n) | 18976 |
| Square | 5072288400 |
| Cube | 361248379848000 |
| Square root | 266.870755 (= 2√17805) |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 143 |
| Scientific notation | 7.122 × |
71220 in other forms
| Form | Value |
|---|---|
| In words | seventy-one thousand two hundred and twenty |
| Binary (base 2) | 10001011000110100 |
| Octal (base 8) | 213064 |
| Hexadecimal (base 16) | 11634 |
| Base 3 | 10121200210 |
| As time | 71220 seconds = 19 h 47 min 0 s |
Is 71220 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (71220 ÷ 2 = 35610) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (71220 ÷ 3 = 23740) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (71220 ÷ 4 = 17805) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (71220 ÷ 5 = 14244) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (71220 ÷ 6 = 11870) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 4) | 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 | Yes (71220 ÷ 10 = 7122) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (71220 ÷ 12 = 5935) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 71220 a prime number?
No. 71220 = × 3 × 5 × 1187, so it is divisible by 2.
What are the factors of 71220?
1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60, 1187, 2374, 3561, 4748, 5935, 7122, 11870, 14244, 17805, 23740, 35610, 71220.
What is 71220 in binary?
10001011000110100 (hexadecimal 11634, octal 213064).
What is the square root of 71220?
About 266.8708, exactly 2√17805.
Is 71220 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 71220?
71220 is a Harshad number: divisible by its digit sum 12.