70
LXX
1000110
The number 70 — factors and divisors
Abundant
70 = 2 × 5 × 7. It has 8 divisors, adding up to 144.
Its divisors, itself excluded, add up to more than the number.
Laid out as dots
It fits as 7 × 10. The more divisors, the closer to a square.
- Prime factors
- 2 × 5 × 7
- Divisors
- 1, 2, 5, 7, 10, 14, 35, 70
- Sum of divisors
- 144
- Sum without itself
- 74
- Coprime below it
- 24
- Digit sum
- 7
- Digital root
- 7
- Roman numeral
- LXX
- Binary
- 1000110
- Octal
- 106
- Hexadecimal
- 46
- Base 36
- 1Y
- Bits
- 7 bits
- Collatz steps
- 14 steps · peaks at 160
- Prime before
- 67
- Prime after
- 71
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 70 a prime number?
No. It breaks down into 2 × 5 × 7.
Q. What are the divisors of 70?
1, 2, 5, 7, 10, 14, 35, 70 — 8 divisors in all, adding up to 144.
Q. How is 70 written in binary?
1000110, which is 7 bits. In hexadecimal it is 46.
Q. How many Collatz steps does 70 take?
It reaches 1 in 14, peaking at 160 on the way.