The number 3720
3720 is a composite number with 32 divisors. Its prime factorisation is × 3 × 5 × 31. Divisors (32): 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 31, 40, 60 … 3720.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 3720: a Harshad number: divisible by its digit sum 12.
- 2
3720 is composite. Its prime factorisation is
- 3
The divisors add up to 11520; without 3720 itself that is 7800, so 3720 is abundant (7800 is more than 3720). Euler's totient φ(3720) = 960 numbers up to 3720 share no factor with it.
- 4
The digits of 3720 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 38 steps to reach 1.
LaTeX source of the formulas on this page
\[ 3720 = 2^{3} \times 3 \times 5 \times 31 \]3720 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 11520 |
| Euler totient φ(n) | 960 |
| Square | 13838400 |
| Cube | 51478848000 |
| Square root | 60.991803 (= 2√930) |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 38 |
| Scientific notation | 3.72 × |
3720 in other forms
| Form | Value |
|---|---|
| In words | three thousand seven hundred and twenty |
| Roman numerals | MMMDCCXX |
| Binary (base 2) | 111010001000 |
| Octal (base 8) | 7210 |
| Hexadecimal (base 16) | E88 |
| Base 3 | 12002210 |
| As time | 3720 seconds = 1 h 2 min 0 s |
Is 3720 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (3720 ÷ 2 = 1860) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (3720 ÷ 3 = 1240) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (3720 ÷ 4 = 930) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (3720 ÷ 5 = 744) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (3720 ÷ 6 = 620) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 (3720 ÷ 8 = 465) | 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 (3720 ÷ 10 = 372) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (3720 ÷ 12 = 310) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 3720 a prime number?
No. 3720 = × 3 × 5 × 31, so it is divisible by 2.
What are the factors of 3720?
1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 31, 40, 60, 62, 93, 120, 124, 155, 186, 248, 310, 372, 465, 620, 744, 930, 1240, 1860, 3720.
What is 3720 in binary?
111010001000 (hexadecimal E88, octal 7210).
What is the square root of 3720?
About 60.9918, exactly 2√930.
What is 3720 in Roman numerals?
MMMDCCXX.
Is 3720 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 3720?
3720 is a Harshad number: divisible by its digit sum 12.