The number 1979
1979 is the 299th prime number. Its only divisors are 1 and 1979.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1979: the 299th prime number.
- 2
1979 is prime, so its only factors are 1 and 1979. It is the 299th prime; the next prime is 1987 and the one before is 1973.
- 3
The divisors add up to 1980; without 1979 itself that is 1, so 1979 is deficient (1 is less than 1979). Euler's totient φ(1979) = 1978 numbers up to 1979 share no factor with it.
- 4
The digits of 1979 add up to 26, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 143 steps to reach 1.
1979 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 1980 |
| Euler totient φ(n) | 1978 |
| Square | 3916441 |
| Cube | 7750636739 |
| Square root | 44.485953 |
| Digit sum / digital root | 26 / 8 |
| Collatz steps to 1 | 143 |
| Scientific notation | 1.979 × |
1979 in other forms
| Form | Value |
|---|---|
| In words | one thousand nine hundred and seventy-nine |
| Roman numerals | MCMLXXIX |
| Binary (base 2) | 11110111011 |
| Octal (base 8) | 3673 |
| Hexadecimal (base 16) | 7BB |
| Base 3 | 2201022 |
| As time | 1979 seconds = 32 min 59 s |
Is 1979 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 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 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 8) | 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 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1979 a prime number?
Yes. 1979 is divisible only by 1 and itself.
What are the factors of 1979?
1, 1979.
What is 1979 in binary?
11110111011 (hexadecimal 7BB, octal 3673).
What is the square root of 1979?
About 44.4860.
What is 1979 in Roman numerals?
MCMLXXIX.
Is 1979 divisible by 3?
No. Its digits add up to 26, which is not a multiple of 3.
What is special about the number 1979?
1979 is the 299th prime number.