49
XLIX
110001
The number 49 — factors and divisors
Deficient
49 = 7². It has 3 divisors, adding up to 57.
Its divisors, itself excluded, add up to less than the number.
Families it belongs to
Square
A number times itself — the dots lay out as a square.
Laid out as dots
It fits as 7 × 7. The more divisors, the closer to a square.
- Prime factors
- 7²
- Divisors
- 1, 7, 49
- Sum of divisors
- 57
- Sum without itself
- 8
- Coprime below it
- 42
- Digit sum
- 13
- Digital root
- 4
- Roman numeral
- XLIX
- Binary
- 110001
- Octal
- 61
- Hexadecimal
- 31
- Base 36
- 1D
- Bits
- 6 bits
- Collatz steps
- 24 steps · peaks at 148
- Prime before
- 47
- Prime after
- 53
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 49 a prime number?
No. It breaks down into 7².
Q. What are the divisors of 49?
1, 7, 49 — 3 divisors in all, adding up to 57.
Q. How is 49 written in binary?
110001, which is 6 bits. In hexadecimal it is 31.
Q. How many Collatz steps does 49 take?
It reaches 1 in 24, peaking at 148 on the way.