154 (one hundred [and] fifty-four) is the natural number following 153 and preceding 155.
In mathematics
154 is a nonagonal number.[1] Its factorization makes 154 a sphenic number.
There is no integer with exactly 154 coprimes below it, making 154 a noncototient, nor is there, in base 10, any integer that added up to its own digits yields 154, making 154 a self number
154 is the sum of the first six factorials, if one starts with and assumes that .
With just 17 cuts, a pancake can be cut up into 154 pieces (Lazy caterer's sequence).[2]
The distinct prime factors of 154 add up to 20, and so do the ones of 153, hence the two form a Ruth-Aaron pair. 154! + 1 is a factorial prime.
References
- ^ "Sloane's A001106 : 9-gonal (or enneagonal or nonagonal) numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
- ^ "Sloane's A000124 : Central polygonal numbers (the Lazy Caterer's sequence)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
- Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1987): 140 - 141
External links
- Virtual Science: Number 154 Archived 2017-06-30 at the Wayback Machine