[[19]] is prime.

Primes up to 19: [[2]], [[3]], [[5]], [[7]], [[11]], [[13]], [[17]], [[19]].

[[19]] is the centered hexagonal number # [[3]].

First 20 centered hexagonal numbers: [[1]], [[7]], [[19]], [[37]], [[61]], [[91]], [[127]], [[169]], [[217]], [[271]], [[331]], [[397]], [[469]], [[547]], [[631]], [[721]], [[817]], [[919]], [[1027]], [[1141]].

[[hz/19]] is closest to [[D#0]] at [[19]] Hz (-40 cents).

Note class: [[D#]], Octave: [[octave/0]].

• [[square]]: 361

• [[square root]]: 4.3589

• [[cube]]: 6859

• [[cube root]]: 2.6684

• [[natural log]] (ln): 2.9444

• [[base-10 log]] (log10): 1.2788

• [[base-2 log]] (log2): 4.2479