Binary 1001111 is 79 in decimal.
The binary number 1000 is the decimal (base 10) number 8. The digits in a binary number are exponents of 2 rather than 10, so that for a four-digit number in binary, the digit places represent 8, 4, 2, 1 1000 (binary) = 8 + (0x4) + (0x2) + (0x1) = 8
10 base ten
55 base 10
21
Some are, some are not. Binary is just a way of writing a number. It will still be divisible be the same numbers it was divisible by in base 10.
A binary number is a number expressed in base-2 numeral system, which uses only two digits: 0 and 1. When you say "of eight," it is unclear what you are referring to. If you are asking about the digit 8 in binary, it is represented as 1000.
The base two is binary. That's where bi- comes from.
The binary number 11111111 represents the number 255 in base 10.
Base 2
The number 21 in binary is 10101
The number 21 in binary is 10101
Binary 1001111 is 79 in decimal.
10
2
Binary describes a number with a base of two.
26 base 10 = 1 1010 base 2