The number 3129
3129 is a composite number with 8 divisors. Its prime factorisation is 3 × 7 × 149. Divisors (8): 1, 3, 7, 21, 149, 447, 1043, 3129.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
3129 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
3129 is composite. Its prime factorisation is
- 3
The divisors add up to 4800; without 3129 itself that is 1671, so 3129 is deficient (1671 is less than 3129). Euler's totient φ(3129) = 1776 numbers up to 3129 share no factor with it.
- 4
The digits of 3129 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 110 steps to reach 1.
LaTeX source of the formulas on this page
\[ 3129 = 3 \times 7 \times 149 \]
3129 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 4800 |
| Euler totient φ(n) | 1776 |
| Square | 9790641 |
| Cube | 30634915689 |
| Square root | 55.937465 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 110 |
| Scientific notation | 3.129 × |
3129 in other forms
| Form | Value |
|---|---|
| In words | three thousand one hundred and twenty-nine |
| Roman numerals | MMMCXXIX |
| Binary (base 2) | 110000111001 |
| Octal (base 8) | 6071 |
| Hexadecimal (base 16) | C39 |
| Base 3 | 11021220 |
| As time | 3129 seconds = 52 min 9 s |
Is 3129 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (3129 ÷ 3 = 1043) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (3129 ÷ 7 = 447) | 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 1) | 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 | No (remainder 9) | 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 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 3129 a prime number?
No. 3129 = 3 × 7 × 149, so it is divisible by 3.
What are the factors of 3129?
1, 3, 7, 21, 149, 447, 1043, 3129.
What is 3129 in binary?
110000111001 (hexadecimal C39, octal 6071).
What is the square root of 3129?
About 55.9375.
What is 3129 in Roman numerals?
MMMCXXIX.
Is 3129 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 3129?
It is a composite number with 8 divisors.