Using Numbers in Text

When writing a novel, there will be numbers used like dates, times, years, ages, money, and just quantities of anything.

Do not start a sentence with a numeral, as it is distracting:

59 tickets were sold last Tuesday.

The common practice is:

Fifty-nine tickets were sold last Tuesday.

Some writers spell out all numbers from one to one hundred and use numerals for anything higher as nine thousand four hundred and sixty-two is a little more wordy than 9462.

“Brian gets £45 an hour,” is somewhat better to read than, “Brian gets fourty-five pounds an hour.”

Conventions on numbers from publisher to publisher varies.
Just stay consistent.