I disagree.
http://grammar.ccc.commnet.edu/grammar/numbers.htm
20.Which one of the following sentences has a number error?
25 people registered for the event.
Sara lost her Social Security number, but she thinks it's 458-71-4782.
Our vacation lasted 10 days and 9 nights.
We received over 10,000 applications
my answer
Sara lost her Social Security number, but she thinks it's 458-71-4782
3 answers
25 people registered for the event.
Correct. You don't start a sentence with a numeral; the number needs to be spelled out at the beginning of a sentence.