133
CXXXIII
10000101
The number 133 — factors and divisors
Deficient
133 = 7 × 19. It has 4 divisors, adding up to 160.
Its divisors, itself excluded, add up to less than the number.
Laid out as dots
It fits as 7 × 19. The more divisors, the closer to a square.
- Prime factors
- 7 × 19
- Divisors
- 1, 7, 19, 133
- Sum of divisors
- 160
- Sum without itself
- 27
- Coprime below it
- 108
- Digit sum
- 7
- Digital root
- 7
- Roman numeral
- CXXXIII
- Binary
- 10000101
- Octal
- 205
- Hexadecimal
- 85
- Base 36
- 3P
- Bits
- 8 bits
- Collatz steps
- 28 steps · peaks at 400
- 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 133 a prime number?
No. It breaks down into 7 × 19.
Q. What are the divisors of 133?
1, 7, 19, 133 — 4 divisors in all, adding up to 160.
Q. How is 133 written in binary?
10000101, which is 8 bits. In hexadecimal it is 85.
Q. How many Collatz steps does 133 take?
It reaches 1 in 28, peaking at 400 on the way.