The number 85420
85420 is a composite number with 12 divisors. Its prime factorisation is × 5 × 4271. Divisors (12): 1, 2, 4, 5, 10, 20, 4271, 8542, 17084, 21355, 42710, 85420.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 85420: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
85420 is composite. Its prime factorisation is
- 3
The divisors add up to 179424; without 85420 itself that is 94004, so 85420 is abundant (94004 is more than 85420). Euler's totient φ(85420) = 34160 numbers up to 85420 share no factor with it.
- 4
The digits of 85420 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 50 steps to reach 1.
LaTeX source of the formulas on this page
\[ 85420 = 2^{2} \times 5 \times 4271 \]85420 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 179424 |
| Euler totient φ(n) | 34160 |
| Square | 7296576400 |
| Cube | 623273556088000 |
| Square root | 292.267001 (= 2√21355) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 50 |
| Scientific notation | 8.542 × |
85420 in other forms
| Form | Value |
|---|---|
| In words | eighty-five thousand four hundred and twenty |
| Binary (base 2) | 10100110110101100 |
| Octal (base 8) | 246654 |
| Hexadecimal (base 16) | 14DAC |
| Base 3 | 11100011201 |
| As time | 85420 seconds = 23 h 43 min 40 s |
Is 85420 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (85420 ÷ 2 = 42710) | 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 | Yes (85420 ÷ 4 = 21355) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (85420 ÷ 5 = 17084) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 4) | 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 | Yes (85420 ÷ 10 = 8542) | 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 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 85420 a prime number?
No. 85420 = × 5 × 4271, so it is divisible by 2.
What are the factors of 85420?
1, 2, 4, 5, 10, 20, 4271, 8542, 17084, 21355, 42710, 85420.
What is 85420 in binary?
10100110110101100 (hexadecimal 14DAC, octal 246654).
What is the square root of 85420?
About 292.2670, exactly 2√21355.
Is 85420 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 85420?
85420 is a happy number: repeatedly adding the squares of its digits reaches 1.