[[1290]] is not prime (composite). Want proof? :)

Full prime factorization: [[2]] * [[3]] * [[5]] * [[43]]

Factor pairs:

[[1290]] = [[2]] * [[645]]

[[1290]] = [[3]] * [[430]]

[[1290]] = [[5]] * [[258]]

[[1290]] = [[6]] * [[215]]

[[1290]] = [[10]] * [[129]]

[[1290]] = [[15]] * [[86]]

[[1290]] = [[30]] * [[43]]

Proper divisors: [[2]], [[3]], [[5]], [[6]], [[10]], [[15]], [[30]], [[43]], [[86]], [[129]], [[215]], [[258]], [[430]], [[645]]

Primes up to 1290: [[2]], [[3]], [[5]], [[7]], [[11]], [[13]], [[17]], [[19]], [[23]], [[29]], [[31]], [[37]], [[41]], [[43]], [[47]], [[53]], [[59]], [[61]], [[67]], [[71]], [[73]], [[79]], [[83]], [[89]], [[97]], [[101]], [[103]], [[107]], [[109]], [[113]], [[127]], [[131]], [[137]], [[139]], [[149]], [[151]], [[157]], [[163]], [[167]], [[173]], [[179]], [[181]], [[191]], [[193]], [[197]], [[199]], [[211]], [[223]], [[227]], [[229]], … (209 total).

[[1290]] is not a centered hexagonal number.

The closest centered hexagonal numbers are [[1261]] (index # [[21]]) and [[1387]] (index # [[22]]).

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/1290]] is closest to [[E6]] at [[1290]] Hz (-38 cents).

Note class: [[E]], Octave: [[octave/6]].

• [[square]]: 1664100

• [[square root]]: 35.9166

• [[cube]]: 2146689000

• [[cube root]]: 10.8859

• [[natural log]] (ln): 7.1624

• [[base-10 log]] (log10): 3.1106

• [[base-2 log]] (log2): 10.3332