07-03-2011, 04:56 PM
129 (one hundred [and] twenty-nine) is the natural number following 128 and preceding 130.
Cardinal one hundred and twenty-nine
Ordinal one hundred and twenty-ninth
Numeral system 129
Factorization
Divisors 1, 3, 43, 129
Roman numeral CXXIX
Binary 100000012
Octal 2018
Duodecimal A912
Hexadecimal 8116
In mathematics 129 is the sum of the first ten prime numbers. It is the smallest number that can be expressed as a sum of three squares in four different ways: 112 + 22 + 22, 102 + 52 + 22, 82 + 82 + 12, and 82 + 72 + 42.
129 is the product of only two primes, 3 and 43, making 129 a semiprime. Since 3 and 43 are both Gaussian primes, this means that 129 is a Blum integer.
129 is a repdigit in base 6 (333).
129 is a happy number.
Please don't ask me to explain any of that
Cardinal one hundred and twenty-nine
Ordinal one hundred and twenty-ninth
Numeral system 129
Factorization
Divisors 1, 3, 43, 129
Roman numeral CXXIX
Binary 100000012
Octal 2018
Duodecimal A912
Hexadecimal 8116
In mathematics 129 is the sum of the first ten prime numbers. It is the smallest number that can be expressed as a sum of three squares in four different ways: 112 + 22 + 22, 102 + 52 + 22, 82 + 82 + 12, and 82 + 72 + 42.
129 is the product of only two primes, 3 and 43, making 129 a semiprime. Since 3 and 43 are both Gaussian primes, this means that 129 is a Blum integer.
129 is a repdigit in base 6 (333).
129 is a happy number.
Please don't ask me to explain any of that