[[263]] is prime.

Primes up to 263: [[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]], … (56 total).

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

The closest centered hexagonal numbers are [[217]] (index #[[9]]) and [[271]] (index #[[10]]).

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]].

• [[square]]: 69169

• [[square root]]: 16.2173

• [[cube]]: 18191447

• [[cube root]]: 6.4070

• [[natural log]] (ln): 5.5722

• [[base-10 log]] (log10): 2.4200

• [[base-2 log]] (log2): 8.0389