411 REFERENCE · Wikipedia
129 (number)
Reference material by Wikipedia contributors. This retains its source identity and is not 411 news reporting.
129 1, 3, 43, 129
129 (one hundred [and] twenty-nine) is the natural number following 128 and preceding 130.
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: , , , and .
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.https://oeis.org/A016105 Sloane's A016105 : Blum integers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-05-27
129 is a repdigit in base 6 (333).
129 is a happy number.https://oeis.org/A007770 Sloane's A007770 : Happy numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-05-27
129 is a centered octahedral number.A001845 Centered octahedral numbers (crystal ball sequence for cubic lattice) 2022-06-02
References
1
Category:Integers