The number 2139
2139 is a composite number with 8 divisors. Its prime factorisation is 3 × 23 × 31. Divisors (8): 1, 3, 23, 31, 69, 93, 713, 2139.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
2139 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
2139 is composite. Its prime factorisation is
- 3
The divisors add up to 3072; without 2139 itself that is 933, so 2139 is deficient (933 is less than 2139). Euler's totient φ(2139) = 1320 numbers up to 2139 share no factor with it.
- 4
The digits of 2139 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 76 steps to reach 1.
LaTeX source of the formulas on this page
\[ 2139 = 3 \times 23 \times 31 \]
2139 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 3072 |
| Euler totient φ(n) | 1320 |
| Square | 4575321 |
| Cube | 9786611619 |
| Square root | 46.249324 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 76 |
| Scientific notation | 2.139 × |
2139 in other forms
| Form | Value |
|---|---|
| In words | two thousand one hundred and thirty-nine |
| Roman numerals | MMCXXXIX |
| Binary (base 2) | 100001011011 |
| Octal (base 8) | 4133 |
| Hexadecimal (base 16) | 85B |
| Base 3 | 2221020 |
| As time | 2139 seconds = 35 min 39 s |
Is 2139 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 (2139 ÷ 3 = 713) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | 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 | 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 3) | 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 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 2139 a prime number?
No. 2139 = 3 × 23 × 31, so it is divisible by 3.
What are the factors of 2139?
1, 3, 23, 31, 69, 93, 713, 2139.
What is 2139 in binary?
100001011011 (hexadecimal 85B, octal 4133).
What is the square root of 2139?
About 46.2493.
What is 2139 in Roman numerals?
MMCXXXIX.
Is 2139 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 2139?
It is a composite number with 8 divisors.