Numbers·199
199
CXCIX
11000111

The number 199 — factors and divisors

Deficient

199 is a prime: only 1 and itself divide it. The prime before is 197, the next is 211.

Its divisors, itself excluded, add up to less than the number.

Families it belongs to

Prime

Nothing divides it but 1 and itself.

Laid out as dots

It only fits in one row. Having no other rectangle is what being prime means.

Prime factors
It does not break down further
Divisors
1, 199
Sum of divisors
200
Sum without itself
1
Coprime below it
198
Digit sum
19
Digital root
1
Roman numeral
CXCIX
Binary
11000111
Octal
307
Hexadecimal
C7
Base 36
5J
Bits
8 bits
Collatz steps
119 steps · peaks at 9,232
Prime before
197
Prime after
211

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.

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 199 a prime number?

Yes. Nothing divides it but 1 and itself.

Q. What are the divisors of 199?

1, 199 — 2 divisors in all, adding up to 200.

Q. How is 199 written in binary?

11000111, which is 8 bits. In hexadecimal it is C7.

Q. How many Collatz steps does 199 take?

It reaches 1 in 119, peaking at 9,232 on the way.