26
XXVI
11010
The number 26 — factors and divisors
Deficient
26 = 2 × 13. It has 4 divisors, adding up to 42.
Its divisors, itself excluded, add up to less than the number.
Laid out as dots
It fits as 2 × 13. The more divisors, the closer to a square.
- Prime factors
- 2 × 13
- Divisors
- 1, 2, 13, 26
- Sum of divisors
- 42
- Sum without itself
- 16
- Coprime below it
- 12
- Digit sum
- 8
- Digital root
- 8
- Roman numeral
- XXVI
- Binary
- 11010
- Octal
- 32
- Hexadecimal
- 1A
- Base 36
- Q
- Bits
- 5 bits
- Collatz steps
- 10 steps · peaks at 40
- Prime before
- 23
- Prime after
- 29
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 26 a prime number?
No. It breaks down into 2 × 13.
Q. What are the divisors of 26?
1, 2, 13, 26 — 4 divisors in all, adding up to 42.
Q. How is 26 written in binary?
11010, which is 5 bits. In hexadecimal it is 1A.
Q. How many Collatz steps does 26 take?
It reaches 1 in 10, peaking at 40 on the way.