Oh, from whom do you know this number? By the way, I am Yanti from Kudus. Please do reply.
Remarks about the translation
in full, punctuation added: Mbak kok tahu nomor ini dari siapa? Oh ya, namaku Yanti dari Kudus. Balas ya mbak. mbak: (Javanese) term of address for an older sister, commonly applied to non-relatives as well; kok: interjection suggesting amazement; namaku: lit. my name is; Kudus a city in Central Java