The number 31600
31600 is a composite number with 30 divisors. Its prime factorisation is × × 79. Divisors (30): 1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 79, 80, 100, 158, 200 … 31600.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31600: a Harshad number: divisible by its digit sum 10.
- 2
31600 is composite. Its prime factorisation is
- 3
The divisors add up to 76880; without 31600 itself that is 45280, so 31600 is abundant (45280 is more than 31600). Euler's totient φ(31600) = 12480 numbers up to 31600 share no factor with it.
- 4
The digits of 31600 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 41 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31600 = 2^{4} \times 5^{2} \times 79 \]31600 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 30 |
| Sum of divisors | 76880 |
| Euler totient φ(n) | 12480 |
| Square | 998560000 |
| Cube | 31554496000000 |
| Square root | 177.763888 (= 20√79) |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 41 |
| Scientific notation | 3.16 × |
31600 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand six hundred |
| Binary (base 2) | 111101101110000 |
| Octal (base 8) | 75560 |
| Hexadecimal (base 16) | 7B70 |
| Base 3 | 1121100101 |
| As time | 31600 seconds = 8 h 46 min 40 s |
Is 31600 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31600 ÷ 2 = 15800) | 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 (31600 ÷ 4 = 7900) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (31600 ÷ 5 = 6320) | 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 2) | 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 (31600 ÷ 8 = 3950) | 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 (31600 ÷ 10 = 3160) | 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 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31600 a prime number?
No. 31600 = × × 79, so it is divisible by 2.
What are the factors of 31600?
1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 79, 80, 100, 158, 200, 316, 395, 400, 632, 790, 1264, 1580, 1975, 3160, 3950, 6320, 7900, 15800, 31600.
What is 31600 in binary?
111101101110000 (hexadecimal 7B70, octal 75560).
What is the square root of 31600?
About 177.7639, exactly 20√79.
Is 31600 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 31600?
31600 is a Harshad number: divisible by its digit sum 10.