You may want to think about splitting the number part into its own field. Look into the Left, LeftWords, Middle, MiddleWords, etc etc functions.
You can use Replace Field contents on the new field to prase out the number and then parse out the street.
Make a backup of your data first as you can not undo.
By the ideals of data normalization, you should separate those into two fields.
Standard USPS is Street Number, Street Name, Street Modifier (Apt # etc)
Long term, it will make things easier for you :)
especially because we have some addresses with 1/2 in them, so those functions would have to be more complicated to handle those...
Interesting to me . . . I'm a bit of a freak for normalization yet I've never considered having street address number in a different field than street address name (a good idea). "Address 2" is in a different field 'tho. . . usually an apartment number or RR. The reason? I never have the need to sort or find by street number or street name. All the same, it's like chicken soup . . . it couldn't hurt!