210
CCX
11010010
The number 210 — factors and divisors
Abundant
210 = 2 × 3 × 5 × 7. It has 16 divisors, adding up to 576.
Its divisors, itself excluded, add up to more than the number.
Families it belongs to
Triangular
The running total of 1, 2, 3 … — the dots stack into a triangle.
Laid out as dots
It fits as 14 × 15. The more divisors, the closer to a square.
- Prime factors
- 2 × 3 × 5 × 7
- Divisors
- 1, 2, 3, 5, 6, 7, 10, 14, 15, 21, 30, 35, 42, 70, 105, 210
- Sum of divisors
- 576
- Sum without itself
- 366
- Coprime below it
- 48
- Digit sum
- 3
- Digital root
- 3
- Roman numeral
- CCX
- Binary
- 11010010
- Octal
- 322
- Hexadecimal
- D2
- Base 36
- 5U
- Bits
- 8 bits
- Collatz steps
- 39 steps · peaks at 808
- Prime before
- 199
- 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.
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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 210 a prime number?
No. It breaks down into 2 × 3 × 5 × 7.
Q. What are the divisors of 210?
1, 2, 3, 5, 6, 7, 10, 14, 15, 21, 30, 35, 42, 70, 105, 210 — 16 divisors in all, adding up to 576.
Q. How is 210 written in binary?
11010010, which is 8 bits. In hexadecimal it is D2.
Q. How many Collatz steps does 210 take?
It reaches 1 in 39, peaking at 808 on the way.