Convert -7 170 171 891 066 907 405 to a Signed Binary (Base 2)

How to convert -7 170 171 891 066 907 405(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 -7 170 171 891 066 907 405 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:

|-7 170 171 891 066 907 405| = 7 170 171 891 066 907 405

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;
  • 7 170 171 891 066 907 405 ÷ 2 = 3 585 085 945 533 453 702 + 1;
  • 3 585 085 945 533 453 702 ÷ 2 = 1 792 542 972 766 726 851 + 0;
  • 1 792 542 972 766 726 851 ÷ 2 = 896 271 486 383 363 425 + 1;
  • 896 271 486 383 363 425 ÷ 2 = 448 135 743 191 681 712 + 1;
  • 448 135 743 191 681 712 ÷ 2 = 224 067 871 595 840 856 + 0;
  • 224 067 871 595 840 856 ÷ 2 = 112 033 935 797 920 428 + 0;
  • 112 033 935 797 920 428 ÷ 2 = 56 016 967 898 960 214 + 0;
  • 56 016 967 898 960 214 ÷ 2 = 28 008 483 949 480 107 + 0;
  • 28 008 483 949 480 107 ÷ 2 = 14 004 241 974 740 053 + 1;
  • 14 004 241 974 740 053 ÷ 2 = 7 002 120 987 370 026 + 1;
  • 7 002 120 987 370 026 ÷ 2 = 3 501 060 493 685 013 + 0;
  • 3 501 060 493 685 013 ÷ 2 = 1 750 530 246 842 506 + 1;
  • 1 750 530 246 842 506 ÷ 2 = 875 265 123 421 253 + 0;
  • 875 265 123 421 253 ÷ 2 = 437 632 561 710 626 + 1;
  • 437 632 561 710 626 ÷ 2 = 218 816 280 855 313 + 0;
  • 218 816 280 855 313 ÷ 2 = 109 408 140 427 656 + 1;
  • 109 408 140 427 656 ÷ 2 = 54 704 070 213 828 + 0;
  • 54 704 070 213 828 ÷ 2 = 27 352 035 106 914 + 0;
  • 27 352 035 106 914 ÷ 2 = 13 676 017 553 457 + 0;
  • 13 676 017 553 457 ÷ 2 = 6 838 008 776 728 + 1;
  • 6 838 008 776 728 ÷ 2 = 3 419 004 388 364 + 0;
  • 3 419 004 388 364 ÷ 2 = 1 709 502 194 182 + 0;
  • 1 709 502 194 182 ÷ 2 = 854 751 097 091 + 0;
  • 854 751 097 091 ÷ 2 = 427 375 548 545 + 1;
  • 427 375 548 545 ÷ 2 = 213 687 774 272 + 1;
  • 213 687 774 272 ÷ 2 = 106 843 887 136 + 0;
  • 106 843 887 136 ÷ 2 = 53 421 943 568 + 0;
  • 53 421 943 568 ÷ 2 = 26 710 971 784 + 0;
  • 26 710 971 784 ÷ 2 = 13 355 485 892 + 0;
  • 13 355 485 892 ÷ 2 = 6 677 742 946 + 0;
  • 6 677 742 946 ÷ 2 = 3 338 871 473 + 0;
  • 3 338 871 473 ÷ 2 = 1 669 435 736 + 1;
  • 1 669 435 736 ÷ 2 = 834 717 868 + 0;
  • 834 717 868 ÷ 2 = 417 358 934 + 0;
  • 417 358 934 ÷ 2 = 208 679 467 + 0;
  • 208 679 467 ÷ 2 = 104 339 733 + 1;
  • 104 339 733 ÷ 2 = 52 169 866 + 1;
  • 52 169 866 ÷ 2 = 26 084 933 + 0;
  • 26 084 933 ÷ 2 = 13 042 466 + 1;
  • 13 042 466 ÷ 2 = 6 521 233 + 0;
  • 6 521 233 ÷ 2 = 3 260 616 + 1;
  • 3 260 616 ÷ 2 = 1 630 308 + 0;
  • 1 630 308 ÷ 2 = 815 154 + 0;
  • 815 154 ÷ 2 = 407 577 + 0;
  • 407 577 ÷ 2 = 203 788 + 1;
  • 203 788 ÷ 2 = 101 894 + 0;
  • 101 894 ÷ 2 = 50 947 + 0;
  • 50 947 ÷ 2 = 25 473 + 1;
  • 25 473 ÷ 2 = 12 736 + 1;
  • 12 736 ÷ 2 = 6 368 + 0;
  • 6 368 ÷ 2 = 3 184 + 0;
  • 3 184 ÷ 2 = 1 592 + 0;
  • 1 592 ÷ 2 = 796 + 0;
  • 796 ÷ 2 = 398 + 0;
  • 398 ÷ 2 = 199 + 0;
  • 199 ÷ 2 = 99 + 1;
  • 99 ÷ 2 = 49 + 1;
  • 49 ÷ 2 = 24 + 1;
  • 24 ÷ 2 = 12 + 0;
  • 12 ÷ 2 = 6 + 0;
  • 6 ÷ 2 = 3 + 0;
  • 3 ÷ 2 = 1 + 1;
  • 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.

7 170 171 891 066 907 405(10) = 110 0011 1000 0001 1001 0001 0101 1000 1000 0001 1000 1000 1010 1011 0000 1101(2)


4. Determine the signed binary number bit length:

  • The base 2 number's actual length, in bits: 63.

  • 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, 63,

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:


7 170 171 891 066 907 405(10) = 0110 0011 1000 0001 1001 0001 0101 1000 1000 0001 1000 1000 1010 1011 0000 1101

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...


-7 170 171 891 066 907 405(10) Base 10 integer number converted and written as a signed binary code (in base 2):

-7 170 171 891 066 907 405(10) = 1110 0011 1000 0001 1001 0001 0101 1000 1000 0001 1000 1000 1010 1011 0000 1101

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