The number 39979
39979 is the 4201st prime number. Its only divisors are 1 and 39979.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 39979: the 4201st prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
39979 is prime, so its only factors are 1 and 39979. It is the 4201st prime; the next prime is 39983 and the one before is 39971.
- 3
The divisors add up to 39980; without 39979 itself that is 1, so 39979 is deficient (1 is less than 39979). Euler's totient φ(39979) = 39978 numbers up to 39979 share no factor with it.
- 4
The digits of 39979 add up to 37, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 93 steps to reach 1.
39979 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 39980 |
| Euler totient φ(n) | 39978 |
| Square | 1598320441 |
| Cube | 63899252910739 |
| Square root | 199.947493 |
| Digit sum / digital root | 37 / 1 |
| Collatz steps to 1 | 93 |
| Scientific notation | 3.9979 × |
39979 in other forms
| Form | Value |
|---|---|
| In words | thirty-nine thousand nine hundred and seventy-nine |
| Binary (base 2) | 1001110000101011 |
| Octal (base 8) | 116053 |
| Hexadecimal (base 16) | 9C2B |
| Base 3 | 2000211201 |
| As time | 39979 seconds = 11 h 6 min 19 s |
Is 39979 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 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | 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 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 39979 a prime number?
Yes. 39979 is divisible only by 1 and itself.
What are the factors of 39979?
1, 39979.
What is 39979 in binary?
1001110000101011 (hexadecimal 9C2B, octal 116053).
What is the square root of 39979?
About 199.9475.
Is 39979 divisible by 3?
No. Its digits add up to 37, which is not a multiple of 3.
What is special about the number 39979?
39979 is the 4201st prime number; a happy number: repeatedly adding the squares of its digits reaches 1.