The number 79800
79800 is a triangular number: 1 + 2 + … + 399 = 79800. Its prime factorisation is × 3 × × 7 × 19. Divisors (96): 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 19, 20, 21, 24 … 79800.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 79800: a triangular number: 1 + 2 + … + 399 = 79800; a Harshad number: divisible by its digit sum 24.
- 2
79800 is composite. Its prime factorisation is
- 3
The divisors add up to 297600; without 79800 itself that is 217800, so 79800 is abundant (217800 is more than 79800). Euler's totient φ(79800) = 17280 numbers up to 79800 share no factor with it.
- 4
The digits of 79800 add up to 24, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 169 steps to reach 1.
LaTeX source of the formulas on this page
\[ 79800 = 2^{3} \times 3 \times 5^{2} \times 7 \times 19 \]79800 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 96 |
| Sum of divisors | 297600 |
| Euler totient φ(n) | 17280 |
| Square | 6368040000 |
| Cube | 508169592000000 |
| Square root | 282.488938 (= 10√798) |
| Digit sum / digital root | 24 / 6 |
| Collatz steps to 1 | 169 |
| Scientific notation | 7.98 × |
79800 in other forms
| Form | Value |
|---|---|
| In words | seventy-nine thousand eight hundred |
| Binary (base 2) | 10011011110111000 |
| Octal (base 8) | 233670 |
| Hexadecimal (base 16) | 137B8 |
| Base 3 | 11001110120 |
| As time | 79800 seconds = 22 h 10 min 0 s |
Is 79800 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (79800 ÷ 2 = 39900) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (79800 ÷ 3 = 26600) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (79800 ÷ 4 = 19950) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (79800 ÷ 5 = 15960) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (79800 ÷ 6 = 13300) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (79800 ÷ 7 = 11400) | 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 | Yes (79800 ÷ 8 = 9975) | 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 | Yes (79800 ÷ 10 = 7980) | 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 | Yes (79800 ÷ 12 = 6650) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 79800 a prime number?
No. 79800 = × 3 × × 7 × 19, so it is divisible by 2.
What are the factors of 79800?
1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 19, 20, 21, 24, 25, 28, 30, 35, 38, 40, 42, 50, 56, 57, 60, 70, 75, 76, 84, 95, 100, 105, 114, 120, 133, 140, 150, 152, 168, 175, 190, 200, 210, 228, 266, 280, 285, 300, 350, 380, 399, 420, 456, 475, 525, 532, 570, 600, 665, 700, 760, 798, 840, 950, 1050, 1064, 1140, 1330, 1400, 1425, 1596, 1900, 1995, 2100, 2280, 2660, 2850, 3192, 3325, 3800, 3990, 4200, 5320, 5700, 6650, 7980, 9975, 11400, 13300, 15960, 19950, 26600, 39900, 79800.
What is 79800 in binary?
10011011110111000 (hexadecimal 137B8, octal 233670).
What is the square root of 79800?
About 282.4889, exactly 10√798.
Is 79800 divisible by 3?
Yes. Its digits add up to 24, a multiple of 3.
What is special about the number 79800?
79800 is a triangular number: 1 + 2 + … + 399 = 79800; a Harshad number: divisible by its digit sum 24.