The number 90210
90210 is a composite number with 32 divisors. Its prime factorisation is 2 × 3 × 5 × 31 × 97. Divisors (32): 1, 2, 3, 5, 6, 10, 15, 30, 31, 62, 93, 97, 155, 186, 194, 291 … 90210.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 90210: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
90210 is composite. Its prime factorisation is
- 3
The divisors add up to 225792; without 90210 itself that is 135582, so 90210 is abundant (135582 is more than 90210). Euler's totient φ(90210) = 23040 numbers up to 90210 share no factor with it.
- 4
The digits of 90210 add up to 12, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 63 steps to reach 1.
LaTeX source of the formulas on this page
\[ 90210 = 2 \times 3 \times 5 \times 31 \times 97 \]
90210 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 225792 |
| Euler totient φ(n) | 23040 |
| Square | 8137844100 |
| Cube | 734114916261000 |
| Square root | 300.349796 |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 63 |
| Scientific notation | 9.021 × |
90210 in other forms
| Form | Value |
|---|---|
| In words | ninety thousand two hundred and ten |
| Binary (base 2) | 10110000001100010 |
| Octal (base 8) | 260142 |
| Hexadecimal (base 16) | 16062 |
| Base 3 | 11120202010 |
| As time | 90210 seconds = 25 h 3 min 30 s |
Is 90210 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (90210 ÷ 2 = 45105) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (90210 ÷ 3 = 30070) | 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 (90210 ÷ 5 = 18042) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (90210 ÷ 6 = 15035) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (90210 ÷ 10 = 9021) | 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 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 90210 a prime number?
No. 90210 = 2 × 3 × 5 × 31 × 97, so it is divisible by 2.
What are the factors of 90210?
1, 2, 3, 5, 6, 10, 15, 30, 31, 62, 93, 97, 155, 186, 194, 291, 310, 465, 485, 582, 930, 970, 1455, 2910, 3007, 6014, 9021, 15035, 18042, 30070, 45105, 90210.
What is 90210 in binary?
10110000001100010 (hexadecimal 16062, octal 260142).
What is the square root of 90210?
About 300.3498.
Is 90210 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 90210?
90210 is a happy number: repeatedly adding the squares of its digits reaches 1.