172
CLXXII
10101100
The number 172 — factors and divisors
Deficient
172 = 2² × 43. It has 6 divisors, adding up to 308.
Its divisors, itself excluded, add up to less than the number.
Laid out as dots
It fits as 4 × 43. The more divisors, the closer to a square.
- Prime factors
- 2² × 43
- Divisors
- 1, 2, 4, 43, 86, 172
- Sum of divisors
- 308
- Sum without itself
- 136
- Coprime below it
- 84
- Digit sum
- 10
- Digital root
- 1
- Roman numeral
- CLXXII
- Binary
- 10101100
- Octal
- 254
- Hexadecimal
- AC
- Base 36
- 4S
- Bits
- 8 bits
- Collatz steps
- 31 steps · peaks at 196
- 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 172 a prime number?
No. It breaks down into 2² × 43.
Q. What are the divisors of 172?
1, 2, 4, 43, 86, 172 — 6 divisors in all, adding up to 308.
Q. How is 172 written in binary?
10101100, which is 8 bits. In hexadecimal it is AC.
Q. How many Collatz steps does 172 take?
It reaches 1 in 31, peaking at 196 on the way.