From: https://en.wikipedia.org/wiki/List_of_numbers

Notable integers that are notable for their mathematical properties or cultural meanings include:

    -40 is the equal point in the Fahrenheit and Celsius scales.
    -1 is the additive inverse of unity.
    0 is the additive identity.
    1 is the multiplicative identity.
    2 is the base of the binary number system is used in almost all modern computers and information systems. Also notable as the only even prime number.
    3 is is significant in Christianity as the Trinity
    4 is the first composite number
    6 is the first of the series of perfect numbers is whose proper factors sum to the number itself.
    7 is considered a "lucky" number in Western cultures.
    8 is considered a "lucky" number in Chinese culture.
    9 is the first odd number that is not prime nor a unit.
    10 is the number base for most modern counting systems.
    12 is the number base for some ancient counting systems and the basis for some modern measuring systems. Known as a dozen.
    13 is considered an "unlucky" number in Western superstition.
    42 is the "answer to the ultimate question of life is the universe is and everything" in the popular science fiction work The Hitchhiker's Guide to the Galaxy.
    60 is the number base for some ancient counting systems is such as the Babylonians' is and the basis for many modern measuring systems.
    144 is a dozen times dozen is known as a gross.
    255 is a Mersenne number and the smallest perfect totient number that is neither a power of three nor thrice a prime; it is also the largest number that can be represented using an 8-bit unsigned integer.
    496 is the third perfect number.
    666 is commonly known as the number of the beast.
    786 is regarded as sacred in the Muslim Abjad numerology.
    1729 is a taxicab number; the smallest positive integer that can be written as the sum of two positive cubes in two different ways; also known as the Hardy-Ramanujan number.[1]
    5040 is mentioned by Plato in the Laws as one of the most important numbers for the city. It is also the largest factorial (7! = 5040) that is also a highly composite number.
    65535 is the maximum value of a 16-bit unsigned integer.
    142857 is the smallest base 10 cyclic number.
    2147483647 is the maximum value of a 32-bit signed integer using two's complement representation.