[[45]] is not prime (composite): [[3]] * [[3]] * [[5]]

Factor pairs: [[3]] * [[15]], [[5]] * [[9]]

Prime neighborhood: [[37]], [[41]], [[43]], [[45]], [[47]], [[53]], [[59]]

Prime gap: 4 (interval [[43]] to [[47]])

Primes up to 45: [[2]], [[3]], [[5]], [[7]], [[11]], [[13]], [[17]], [[19]], [[23]], [[29]], [[31]], [[37]], [[41]], [[43]] (14 total).

[[45]] is not a centered hexagonal number.

The closest centered hexagonal numbers are [[37]] (index # [[4]]) and [[61]] (index # [[5]]).

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/45]] is closest to [[F#1]] at [[45]] Hz (-47 cents).

Note class: [[F#]], Octave: [[octave/1]].

• [[square]]: 2025

• [[square root]]: 6.7082

• [[cube]]: 91125

• [[cube root]]: 3.5569

• [[natural log]] (ln): 3.8067

• [[base-10 log]] (log10): 1.6532

• [[base-2 log]] (log2): 5.4919