135
CXXXV
10000111
The number 135 — factors and divisors
Deficient
135 = 3³ × 5. It has 8 divisors, adding up to 240.
Its divisors, itself excluded, add up to less than the number.
Laid out as dots
It fits as 9 × 15. The more divisors, the closer to a square.
- Prime factors
- 3³ × 5
- Divisors
- 1, 3, 5, 9, 15, 27, 45, 135
- Sum of divisors
- 240
- Sum without itself
- 105
- Coprime below it
- 72
- Digit sum
- 9
- Digital root
- 9
- Roman numeral
- CXXXV
- Binary
- 10000111
- Octal
- 207
- Hexadecimal
- 87
- Base 36
- 3R
- Bits
- 8 bits
- Collatz steps
- 41 steps · peaks at 916
- Prime before
- 131
- Prime after
- 137
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 135 a prime number?
No. It breaks down into 3³ × 5.
Q. What are the divisors of 135?
1, 3, 5, 9, 15, 27, 45, 135 — 8 divisors in all, adding up to 240.
Q. How is 135 written in binary?
10000111, which is 8 bits. In hexadecimal it is 87.
Q. How many Collatz steps does 135 take?
It reaches 1 in 41, peaking at 916 on the way.