六ろく十じゅう四し分ぶ音おん符ぷ

Meanings

1

64th note; hemidemisemiquaver; semidemisemiquaver

A note with a duration of 1/64 of a whole note, used in music notation.

符token, sign, mark

三さん十じゅう二に分ぶ音おん符ぷ
三十二分音符 is a 32nd note (twice as long as a 六十四分音符), and their similar naming pattern makes them easy to mix up.
十じゅう六ろく分ぶ音おん符ぷ
十六分音符 is a 16th note (four times as long as a 六十四分音符), and learners often confuse these fractional note names.

個こN5
六十四分音符 is counted with 個, the general counter used for individual printed musical notes.

Compound of 六十四 (sixty-four) + 分 (division) + 音符 (musical note).