what is the largest prime no that is stored in 7 bit pattern?

Question

How to calculate prime no in bit pattern..??

Answer 1

7 bits goes up to 2^7 - 1 = 127. Since 127 is itself prime, 127 is the largest prime that can be stored in 7 bits. I don't think there's a formula to generalize this for different numbers of bits, so you'd need to use a table of primes.

Answer 2

As often happens, the real answer is "it depends". 7 bits can be used to store non-negative integers, in which caseas others have said it is the largest prime number < 2^7, or 127.

If the 7 bits store positive or negative integers in one's complement, then it is the largest prime < 63, or 61.

While for 7 bits this would be a little odd, if you asked for a larger number it could be storing a real number, with mantissa and exponent.

Some older computers worked in decimal, where 4 bits gave a single decimal digit. So there are lots of possibilities, depending on how the bits are interpreted. (in a program I could use 7 bits to index the primes, in which case the largest prime number stored would be 719, I think , the 128th prime). But you probably want 127.

Answer 3

I have no idea of calculating prime number in bit pattern. But the largest prime number that can be stored in a 7-bit binary pattern is 127. It will be written as: 1111111 in binary.

Answer 4

1111111, i.e. 127 base ten is prime.

A related question is to ask which numbers of the binary form 111111....1111 are prime. These numbers are called Mersenne primes.

Answer 5

1111111 i.e, 127