Convert 1 010 000 110 111 221 to a Signed Binary (Base 2)

How to convert 1 010 000 110 111 221(10), a signed base 10 integer number? How to write it as a signed binary code in base 2

What are the required steps to convert base 10 integer
number 1 010 000 110 111 221 to signed binary code (in base 2)?

  • A signed integer, written in base ten, or a decimal system number, is a number written using the digits 0 through 9 and the sign, which can be positive (+) or negative (-). If positive, the sign is usually not written. A number written in base two, or binary, is a number written using only the digits 0 and 1.

1. Divide the number repeatedly by 2:

Keep track of each remainder.

Stop when you get a quotient that is equal to zero.


  • division = quotient + remainder;
  • 1 010 000 110 111 221 ÷ 2 = 505 000 055 055 610 + 1;
  • 505 000 055 055 610 ÷ 2 = 252 500 027 527 805 + 0;
  • 252 500 027 527 805 ÷ 2 = 126 250 013 763 902 + 1;
  • 126 250 013 763 902 ÷ 2 = 63 125 006 881 951 + 0;
  • 63 125 006 881 951 ÷ 2 = 31 562 503 440 975 + 1;
  • 31 562 503 440 975 ÷ 2 = 15 781 251 720 487 + 1;
  • 15 781 251 720 487 ÷ 2 = 7 890 625 860 243 + 1;
  • 7 890 625 860 243 ÷ 2 = 3 945 312 930 121 + 1;
  • 3 945 312 930 121 ÷ 2 = 1 972 656 465 060 + 1;
  • 1 972 656 465 060 ÷ 2 = 986 328 232 530 + 0;
  • 986 328 232 530 ÷ 2 = 493 164 116 265 + 0;
  • 493 164 116 265 ÷ 2 = 246 582 058 132 + 1;
  • 246 582 058 132 ÷ 2 = 123 291 029 066 + 0;
  • 123 291 029 066 ÷ 2 = 61 645 514 533 + 0;
  • 61 645 514 533 ÷ 2 = 30 822 757 266 + 1;
  • 30 822 757 266 ÷ 2 = 15 411 378 633 + 0;
  • 15 411 378 633 ÷ 2 = 7 705 689 316 + 1;
  • 7 705 689 316 ÷ 2 = 3 852 844 658 + 0;
  • 3 852 844 658 ÷ 2 = 1 926 422 329 + 0;
  • 1 926 422 329 ÷ 2 = 963 211 164 + 1;
  • 963 211 164 ÷ 2 = 481 605 582 + 0;
  • 481 605 582 ÷ 2 = 240 802 791 + 0;
  • 240 802 791 ÷ 2 = 120 401 395 + 1;
  • 120 401 395 ÷ 2 = 60 200 697 + 1;
  • 60 200 697 ÷ 2 = 30 100 348 + 1;
  • 30 100 348 ÷ 2 = 15 050 174 + 0;
  • 15 050 174 ÷ 2 = 7 525 087 + 0;
  • 7 525 087 ÷ 2 = 3 762 543 + 1;
  • 3 762 543 ÷ 2 = 1 881 271 + 1;
  • 1 881 271 ÷ 2 = 940 635 + 1;
  • 940 635 ÷ 2 = 470 317 + 1;
  • 470 317 ÷ 2 = 235 158 + 1;
  • 235 158 ÷ 2 = 117 579 + 0;
  • 117 579 ÷ 2 = 58 789 + 1;
  • 58 789 ÷ 2 = 29 394 + 1;
  • 29 394 ÷ 2 = 14 697 + 0;
  • 14 697 ÷ 2 = 7 348 + 1;
  • 7 348 ÷ 2 = 3 674 + 0;
  • 3 674 ÷ 2 = 1 837 + 0;
  • 1 837 ÷ 2 = 918 + 1;
  • 918 ÷ 2 = 459 + 0;
  • 459 ÷ 2 = 229 + 1;
  • 229 ÷ 2 = 114 + 1;
  • 114 ÷ 2 = 57 + 0;
  • 57 ÷ 2 = 28 + 1;
  • 28 ÷ 2 = 14 + 0;
  • 14 ÷ 2 = 7 + 0;
  • 7 ÷ 2 = 3 + 1;
  • 3 ÷ 2 = 1 + 1;
  • 1 ÷ 2 = 0 + 1;

2. Construct the base 2 representation of the positive number:

Take all the remainders starting from the bottom of the list constructed above.

1 010 000 110 111 221(10) = 11 1001 0110 1001 0110 1111 1001 1100 1001 0100 1001 1111 0101(2)


3. Determine the signed binary number bit length:

  • The base 2 number's actual length, in bits: 50.

  • A signed binary's bit length must be equal to a power of 2, as of:
  • 21 = 2; 22 = 4; 23 = 8; 24 = 16; 25 = 32; 26 = 64; ...
  • The first bit (the leftmost) is reserved for the sign:
  • 0 = positive integer number, 1 = negative integer number

The least number that is:


1) a power of 2

2) and is larger than the actual length, 50,

3) so that the first bit (leftmost) could be zero
(we deal with a positive number at this moment)


=== is: 64.


4. Get the positive binary computer representation on 64 bits (8 Bytes):

If needed, add extra 0s in front (to the left) of the base 2 number, up to the required length, 64:


1 010 000 110 111 221(10) Base 10 integer number converted and written as a signed binary code (in base 2):

1 010 000 110 111 221(10) = 0000 0000 0000 0011 1001 0110 1001 0110 1111 1001 1100 1001 0100 1001 1111 0101

Spaces were used to group digits: for binary, by 4, for decimal, by 3.


How to convert signed base 10 integers in decimal to binary code system

Follow the steps below to convert a signed base ten integer number to signed binary:

  • 1. In a signed binary, first bit (the leftmost) is reserved for sign: 0 = positive integer number, 1 = positive integer number. If the number to be converted is negative, start with its positive version.
  • 2. Divide repeatedly by 2 the positive integer number keeping track of each remainder. STOP when we get a quotient that is ZERO.
  • 3. Construct the base 2 representation of the positive number, by taking all the remainders starting from the bottom of the list constructed above. Thus, the last remainder of the divisions becomes the first symbol (the leftmost) of the base two number, while the first remainder becomes the last symbol (the rightmost).
  • 4. Binary numbers represented in computer language have a length of 4, 8, 16, 32, 64, ... bits (power of 2) - if needed, fill in extra '0' bits in front of the base 2 number (to the left), up to the right length; this way the first bit (the leftmost one) is always '0', as for a positive representation.
  • 5. To get the negative reprezentation of the number, simply switch the first bit (the leftmost one), from '0' to '1'.

Example: convert the negative number -63 from decimal system (base ten) to signed binary code system:

  • 1. Start with the positive version of the number: |-63| = 63;
  • 2. Divide repeatedly 63 by 2, keeping track of each remainder, until we get a quotient that is equal to zero:
    • division = quotient + remainder
    • 63 ÷ 2 = 31 + 1
    • 31 ÷ 2 = 15 + 1
    • 15 ÷ 2 = 7 + 1
    • 7 ÷ 2 = 3 + 1
    • 3 ÷ 2 = 1 + 1
    • 1 ÷ 2 = 0 + 1
  • 3. Construct the base 2 representation of the positive number, by taking all the remainders starting from the bottom of the list constructed above:
    63(10) = 11 1111(2)
  • 4. The actual length of base 2 representation number is 6, so the positive binary computer representation length of the signed binary will take in this case 8 bits (the least power of 2 higher than 6) - add extra '0's in front (to the left), up to the required length; this way the first bit (the leftmost one) is to be '0', as for a positive number:
    63(10) = 0011 1111(2)
  • 5. To get the negative integer number representation simply change the first bit (the leftmost), from '0' to '1':
    -63(10) = 1011 1111
  • Number -63(10), signed integer, converted from decimal system (base 10) to signed binary = 1011 1111