The number 1551
1551 is a palindrome: it reads 1551 backwards too. Its prime factorisation is 3 × 11 × 47. Divisors (8): 1, 3, 11, 33, 47, 141, 517, 1551.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1551: a palindrome: it reads 1551 backwards too.
- 2
1551 is composite. Its prime factorisation is
- 3
The divisors add up to 2304; without 1551 itself that is 753, so 1551 is deficient (753 is less than 1551). Euler's totient φ(1551) = 920 numbers up to 1551 share no factor with it.
- 4
The digits of 1551 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 153 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1551 = 3 \times 11 \times 47 \]
1551 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 2304 |
| Euler totient φ(n) | 920 |
| Square | 2405601 |
| Cube | 3731087151 |
| Square root | 39.382737 |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 153 |
| Scientific notation | 1.551 × |
1551 in other forms
| Form | Value |
|---|---|
| In words | one thousand five hundred and fifty-one |
| Roman numerals | MDLI |
| Binary (base 2) | 11000001111 |
| Octal (base 8) | 3017 |
| Hexadecimal (base 16) | 60F |
| Base 3 | 2010110 |
| As time | 1551 seconds = 25 min 51 s |
Is 1551 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (1551 ÷ 3 = 517) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 7) | 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 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (1551 ÷ 11 = 141) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1551 a prime number?
No. 1551 = 3 × 11 × 47, so it is divisible by 3.
What are the factors of 1551?
1, 3, 11, 33, 47, 141, 517, 1551.
What is 1551 in binary?
11000001111 (hexadecimal 60F, octal 3017).
What is the square root of 1551?
About 39.3827.
What is 1551 in Roman numerals?
MDLI.
Is 1551 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 1551?
1551 is a palindrome: it reads 1551 backwards too.