The below table visualizes how the decimal number 129 equals the binary number 10000001.

1 | × | 2^{7} | = | 128 | |

+ | 0 | × | 2^{6} | = | 0 |

+ | 0 | × | 2^{5} | = | 0 |

+ | 0 | × | 2^{4} | = | 0 |

+ | 0 | × | 2^{3} | = | 0 |

+ | 0 | × | 2^{2} | = | 0 |

+ | 0 | × | 2^{1} | = | 0 |

+ | 1 | × | 2^{0} | = | 1 |

= | 129 |

Binary numbers are a positional numeral system with the base (or "radix") 2. This means that binary digit (or "bit") only has two states: 1 and 0. As a result, binary numbers are well suited for electronic circuits since they can be represented as ON or OFF states, and they're therefore used as the fundamental data format in computers. A collection of 8 bits is commonly referred to as Byte. There are 2^{8} different combinations of bits in a byte, and it can therefore be used to represent integers between 0 and 255. To represent one quadrillion (the largest number supported on integers.info), a total of 50 bits are required.