The number 139
139 is a twin prime (137 and 139 are both prime) and the 34th prime number. Its only divisors are 1 and 139.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 139: a twin prime (137 and 139 are both prime); the 34th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
139 is prime, so its only factors are 1 and 139. It is the 34th prime; the next prime is 149 and the one before is 137.
- 3
The divisors add up to 140; without 139 itself that is 1, so 139 is deficient (1 is less than 139). Euler's totient φ(139) = 138 numbers up to 139 share no factor with it.
- 4
The digits of 139 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 41 steps to reach 1.
139 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 140 |
| Euler totient φ(n) | 138 |
| Square | 19321 |
| Cube | 2685619 |
| Square root | 11.789826 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 41 |
| Scientific notation | 1.39 × |
139 in other forms
| Form | Value |
|---|---|
| In words | one hundred and thirty-nine |
| Roman numerals | CXXXIX |
| Binary (base 2) | 10001011 |
| Octal (base 8) | 213 |
| Hexadecimal (base 16) | 8B |
| Base 3 | 12011 |
| As time | 139 seconds = 2 min 19 s |
Is 139 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 | No (remainder 1) | 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 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 4) | 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 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 139 a prime number?
Yes. 139 is divisible only by 1 and itself.
What are the factors of 139?
1, 139.
What is 139 in binary?
10001011 (hexadecimal 8B, octal 213).
What is the square root of 139?
About 11.7898.
What is 139 in Roman numerals?
CXXXIX.
Is 139 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 139?
139 is a twin prime (137 and 139 are both prime); the 34th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.