154 (number)

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 ${\displaystyle 0!}$ and assumes that ${\displaystyle 0!=1}$.

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.