163840000domain: NAppears in sequencesGreatest common divisor of n! and n^n.at n=19A051696a(n)=Product{k=0..n, 1+3^A101650(k)}/2.at n=13A101658Cancellation factor in reducing Sum_{k=0...n} n^k/k! to lowest terms.at n=19A214402Largest unitary square divisor of n!.at n=21A374988