The number 51990
51990 is a composite number with 16 divisors. Its prime factorisation is 2 × 3 × 5 × 1733. Divisors (16): 1, 2, 3, 5, 6, 10, 15, 30, 1733, 3466, 5199, 8665, 10398, 17330, 25995, 51990.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 51990: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
51990 is composite. Its prime factorisation is
- 3
The divisors add up to 124848; without 51990 itself that is 72858, so 51990 is abundant (72858 is more than 51990). Euler's totient φ(51990) = 13856 numbers up to 51990 share no factor with it.
- 4
The digits of 51990 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 127 steps to reach 1.
LaTeX source of the formulas on this page
\[ 51990 = 2 \times 3 \times 5 \times 1733 \]
51990 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 124848 |
| Euler totient φ(n) | 13856 |
| Square | 2702960100 |
| Cube | 140526895599000 |
| Square root | 228.013158 |
| Digit sum / digital root | 24 / 6 |
| Collatz steps to 1 | 127 |
| Scientific notation | 5.199 × |
51990 in other forms
| Form | Value |
|---|---|
| In words | fifty-one thousand nine hundred and ninety |
| Binary (base 2) | 1100101100010110 |
| Octal (base 8) | 145426 |
| Hexadecimal (base 16) | CB16 |
| Base 3 | 2122022120 |
| As time | 51990 seconds = 14 h 26 min 30 s |
Is 51990 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (51990 ÷ 2 = 25995) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (51990 ÷ 3 = 17330) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (51990 ÷ 5 = 10398) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (51990 ÷ 6 = 8665) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 6) | 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 (51990 ÷ 10 = 5199) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 51990 a prime number?
No. 51990 = 2 × 3 × 5 × 1733, so it is divisible by 2.
What are the factors of 51990?
1, 2, 3, 5, 6, 10, 15, 30, 1733, 3466, 5199, 8665, 10398, 17330, 25995, 51990.
What is 51990 in binary?
1100101100010110 (hexadecimal CB16, octal 145426).
What is the square root of 51990?
About 228.0132.
Is 51990 divisible by 3?
Yes. Its digits add up to 24, a multiple of 3.
What is special about the number 51990?
51990 is a happy number: repeatedly adding the squares of its digits reaches 1.