170
CLXX
10101010
The number 170 — factors and divisors
Deficient
170 = 2 × 5 × 17. It has 8 divisors, adding up to 324.
Its divisors, itself excluded, add up to less than the number.
Laid out as dots
It fits as 10 × 17. The more divisors, the closer to a square.
- Prime factors
- 2 × 5 × 17
- Divisors
- 1, 2, 5, 10, 17, 34, 85, 170
- Sum of divisors
- 324
- Sum without itself
- 154
- Coprime below it
- 64
- Digit sum
- 8
- Digital root
- 8
- Roman numeral
- CLXX
- Binary
- 10101010
- Octal
- 252
- Hexadecimal
- AA
- Base 36
- 4Q
- Bits
- 8 bits
- Collatz steps
- 10 steps · peaks at 256
- Prime before
- 167
- Prime after
- 173
The grid
Ten per row, twenty rows. The filled cells are primes — you can see the multiples of 2 and 5 drop out in columns.
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Numbers either side
How to read this
- The prime factors are what the number is made of. The count and sum of divisors both follow from them.
- Add the divisors, take the number away, and you get perfect, abundant or deficient.
- The length of the binary form is the bit count. 255 taking eight digits is what a byte is.
- Collatz: halve it if even, triple it and add one if odd. The count is how many moves reach 1.
Frequently asked questions
Q. Is 170 a prime number?
No. It breaks down into 2 × 5 × 17.
Q. What are the divisors of 170?
1, 2, 5, 10, 17, 34, 85, 170 — 8 divisors in all, adding up to 324.
Q. How is 170 written in binary?
10101010, which is 8 bits. In hexadecimal it is AA.
Q. How many Collatz steps does 170 take?
It reaches 1 in 10, peaking at 256 on the way.