The number 21502
21502 is a composite number with 8 divisors. Its prime factorisation is 2 × 13 × 827. Divisors (8): 1, 2, 13, 26, 827, 1654, 10751, 21502.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21502 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21502 is composite. Its prime factorisation is
- 3
The divisors add up to 34776; without 21502 itself that is 13274, so 21502 is deficient (13274 is less than 21502). Euler's totient φ(21502) = 9912 numbers up to 21502 share no factor with it.
- 4
The digits of 21502 add up to 10, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 193 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21502 = 2 \times 13 \times 827 \]
21502 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 34776 |
| Euler totient φ(n) | 9912 |
| Square | 462336004 |
| Cube | 9941148758008 |
| Square root | 146.635603 |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 193 |
| Scientific notation | 2.1502 × |
21502 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand five hundred and two |
| Binary (base 2) | 101001111111110 |
| Octal (base 8) | 51776 |
| Hexadecimal (base 16) | 53FE |
| Base 3 | 1002111101 |
| As time | 21502 seconds = 5 h 58 min 22 s |
Is 21502 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21502 ÷ 2 = 10751) | 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 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | 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 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 6) | 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 | No (remainder 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21502 a prime number?
No. 21502 = 2 × 13 × 827, so it is divisible by 2.
What are the factors of 21502?
1, 2, 13, 26, 827, 1654, 10751, 21502.
What is 21502 in binary?
101001111111110 (hexadecimal 53FE, octal 51776).
What is the square root of 21502?
About 146.6356.
Is 21502 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 21502?
It is a composite number with 8 divisors.