The number 149
149 is a twin prime (149 and 151 are both prime) and the 35th prime number. Its only divisors are 1 and 149.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 149: a twin prime (149 and 151 are both prime); the 35th prime number.
- 2
149 is prime, so its only factors are 1 and 149. It is the 35th prime; the next prime is 151 and the one before is 139.
- 3
The divisors add up to 150; without 149 itself that is 1, so 149 is deficient (1 is less than 149). Euler's totient φ(149) = 148 numbers up to 149 share no factor with it.
- 4
The digits of 149 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 23 steps to reach 1.
149 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 150 |
| Euler totient φ(n) | 148 |
| Square | 22201 |
| Cube | 3307949 |
| Square root | 12.206556 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 23 |
| Scientific notation | 1.49 × |
149 in other forms
| Form | Value |
|---|---|
| In words | one hundred and forty-nine |
| Roman numerals | CXLIX |
| Binary (base 2) | 10010101 |
| Octal (base 8) | 225 |
| Hexadecimal (base 16) | 95 |
| Base 3 | 12112 |
| As time | 149 seconds = 2 min 29 s |
Is 149 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 2) | 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 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | 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 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 149 a prime number?
Yes. 149 is divisible only by 1 and itself.
What are the factors of 149?
1, 149.
What is 149 in binary?
10010101 (hexadecimal 95, octal 225).
What is the square root of 149?
About 12.2066.
What is 149 in Roman numerals?
CXLIX.
Is 149 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 149?
149 is a twin prime (149 and 151 are both prime); the 35th prime number.