SQL error “ORA-01722: invalid number”

A very easy one for someone, The following insert is giving me the

ORA-01722: invalid number

why?

INSERT INTO CUSTOMER VALUES (1,'MALADY','Claire','27 Smith St Caulfield','0419 853 694');
INSERT INTO CUSTOMER VALUES (2,'GIBSON','Jake','27 Smith St Caulfield','0415 713 598');
INSERT INTO CUSTOMER VALUES (3,'LUU','Barry','5  Jones St Malvern','0413 591 341');
INSERT INTO CUSTOMER VALUES (4,'JONES','Michael','7  Smith St Caulfield','0419 853 694');
INSERT INTO CUSTOMER VALUES (5,'MALADY','Betty','27 Smith St Knox','0418 418 347');