[[86]] is not prime (composite). Want proof? :)

Full prime factorization: [[2]] * [[43]]

Factor pairs:

[[86]] = [[2]] * [[43]]

Proper divisors: [[2]], [[43]]

Primes up to 86: [[2]], [[3]], [[5]], [[7]], [[11]], [[13]], [[17]], [[19]], [[23]], [[29]], [[31]], [[37]], [[41]], [[43]], [[47]], [[53]], [[59]], [[61]], [[67]], [[71]], [[73]], [[79]], [[83]].

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

The closest centered hexagonal numbers are [[61]] (index # [[5]]) and [[91]] (index # [[6]]).

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/86]] is closest to [[F2]] at [[86]] Hz (-26 cents).

Note class: [[F]], Octave: [[octave/2]].

• [[square]]: 7396

• [[square root]]: 9.2736

• [[cube]]: 636056

• [[cube root]]: 4.4140

• [[natural log]] (ln): 4.4543

• [[base-10 log]] (log10): 1.9345

• [[base-2 log]] (log2): 6.4263