Convert -289 229 853 136 545 to a Signed Binary (Base 2)

How to convert -289 229 853 136 545(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 -289 229 853 136 545 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. Start with the positive version of the number:

|-289 229 853 136 545| = 289 229 853 136 545

2. 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;
  • 289 229 853 136 545 ÷ 2 = 144 614 926 568 272 + 1;
  • 144 614 926 568 272 ÷ 2 = 72 307 463 284 136 + 0;
  • 72 307 463 284 136 ÷ 2 = 36 153 731 642 068 + 0;
  • 36 153 731 642 068 ÷ 2 = 18 076 865 821 034 + 0;
  • 18 076 865 821 034 ÷ 2 = 9 038 432 910 517 + 0;
  • 9 038 432 910 517 ÷ 2 = 4 519 216 455 258 + 1;
  • 4 519 216 455 258 ÷ 2 = 2 259 608 227 629 + 0;
  • 2 259 608 227 629 ÷ 2 = 1 129 804 113 814 + 1;
  • 1 129 804 113 814 ÷ 2 = 564 902 056 907 + 0;
  • 564 902 056 907 ÷ 2 = 282 451 028 453 + 1;
  • 282 451 028 453 ÷ 2 = 141 225 514 226 + 1;
  • 141 225 514 226 ÷ 2 = 70 612 757 113 + 0;
  • 70 612 757 113 ÷ 2 = 35 306 378 556 + 1;
  • 35 306 378 556 ÷ 2 = 17 653 189 278 + 0;
  • 17 653 189 278 ÷ 2 = 8 826 594 639 + 0;
  • 8 826 594 639 ÷ 2 = 4 413 297 319 + 1;
  • 4 413 297 319 ÷ 2 = 2 206 648 659 + 1;
  • 2 206 648 659 ÷ 2 = 1 103 324 329 + 1;
  • 1 103 324 329 ÷ 2 = 551 662 164 + 1;
  • 551 662 164 ÷ 2 = 275 831 082 + 0;
  • 275 831 082 ÷ 2 = 137 915 541 + 0;
  • 137 915 541 ÷ 2 = 68 957 770 + 1;
  • 68 957 770 ÷ 2 = 34 478 885 + 0;
  • 34 478 885 ÷ 2 = 17 239 442 + 1;
  • 17 239 442 ÷ 2 = 8 619 721 + 0;
  • 8 619 721 ÷ 2 = 4 309 860 + 1;
  • 4 309 860 ÷ 2 = 2 154 930 + 0;
  • 2 154 930 ÷ 2 = 1 077 465 + 0;
  • 1 077 465 ÷ 2 = 538 732 + 1;
  • 538 732 ÷ 2 = 269 366 + 0;
  • 269 366 ÷ 2 = 134 683 + 0;
  • 134 683 ÷ 2 = 67 341 + 1;
  • 67 341 ÷ 2 = 33 670 + 1;
  • 33 670 ÷ 2 = 16 835 + 0;
  • 16 835 ÷ 2 = 8 417 + 1;
  • 8 417 ÷ 2 = 4 208 + 1;
  • 4 208 ÷ 2 = 2 104 + 0;
  • 2 104 ÷ 2 = 1 052 + 0;
  • 1 052 ÷ 2 = 526 + 0;
  • 526 ÷ 2 = 263 + 0;
  • 263 ÷ 2 = 131 + 1;
  • 131 ÷ 2 = 65 + 1;
  • 65 ÷ 2 = 32 + 1;
  • 32 ÷ 2 = 16 + 0;
  • 16 ÷ 2 = 8 + 0;
  • 8 ÷ 2 = 4 + 0;
  • 4 ÷ 2 = 2 + 0;
  • 2 ÷ 2 = 1 + 0;
  • 1 ÷ 2 = 0 + 1;

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

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

289 229 853 136 545(10) = 1 0000 0111 0000 1101 1001 0010 1010 0111 1001 0110 1010 0001(2)


4. Determine the signed binary number bit length:

  • The base 2 number's actual length, in bits: 49.

  • 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, 49,

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


=== is: 64.


5. 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:


289 229 853 136 545(10) = 0000 0000 0000 0001 0000 0111 0000 1101 1001 0010 1010 0111 1001 0110 1010 0001

6. Get the negative integer number representation:

To get the negative integer number representation on 64 bits (8 Bytes),


... change the first bit (the leftmost), from 0 to 1...


-289 229 853 136 545(10) Base 10 integer number converted and written as a signed binary code (in base 2):

-289 229 853 136 545(10) = 1000 0000 0000 0001 0000 0111 0000 1101 1001 0010 1010 0111 1001 0110 1010 0001

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