The number 74820
74820 is a composite number with 48 divisors. Its prime factorisation is × 3 × 5 × 29 × 43. Divisors (48): 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 29, 30, 43, 58, 60, 86 … 74820.
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How to work it out
- 1
What is special about 74820: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
74820 is composite. Its prime factorisation is
- 3
The divisors add up to 221760; without 74820 itself that is 146940, so 74820 is abundant (146940 is more than 74820). Euler's totient φ(74820) = 18816 numbers up to 74820 share no factor with it.
- 4
The digits of 74820 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 63 steps to reach 1.
LaTeX source of the formulas on this page
\[ 74820 = 2^{2} \times 3 \times 5 \times 29 \times 43 \]74820 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 48 |
| Sum of divisors | 221760 |
| Euler totient φ(n) | 18816 |
| Square | 5598032400 |
| Cube | 418844784168000 |
| Square root | 273.532448 (= 2√18705) |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 63 |
| Scientific notation | 7.482 × |
74820 in other forms
| Form | Value |
|---|---|
| In words | seventy-four thousand eight hundred and twenty |
| Binary (base 2) | 10010010001000100 |
| Octal (base 8) | 222104 |
| Hexadecimal (base 16) | 12444 |
| Base 3 | 10210122010 |
| As time | 74820 seconds = 20 h 47 min 0 s |
Is 74820 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (74820 ÷ 2 = 37410) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (74820 ÷ 3 = 24940) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (74820 ÷ 4 = 18705) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (74820 ÷ 5 = 14964) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (74820 ÷ 6 = 12470) | 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 | 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 (74820 ÷ 10 = 7482) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (74820 ÷ 12 = 6235) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 74820 a prime number?
No. 74820 = × 3 × 5 × 29 × 43, so it is divisible by 2.
What are the factors of 74820?
1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 29, 30, 43, 58, 60, 86, 87, 116, 129, 145, 172, 174, 215, 258, 290, 348, 430, 435, 516, 580, 645, 860, 870, 1247, 1290, 1740, 2494, 2580, 3741, 4988, 6235, 7482, 12470, 14964, 18705, 24940, 37410, 74820.
What is 74820 in binary?
10010010001000100 (hexadecimal 12444, octal 222104).
What is the square root of 74820?
About 273.5324, exactly 2√18705.
Is 74820 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 74820?
74820 is a happy number: repeatedly adding the squares of its digits reaches 1.