Alex Bellos, a blogger for The Guardian, polled people on their preferred number:

• People often pick numbers related to their birthdays or other key dates.
• Odd numbers are more popular than even ones
• Whole numbers are disliked. This might be because we round off to whole numbers and so we think they’re imprecise. If you want a favourite number it may as well be a number that stands for itself.
• Prime numbers are popular – people like to be unique.
• Eight is popular because in Chinese it sounds like “prosperity”. Four sounds like “death” and is disliked.
• Three is well regarded. Religion is filled with that number, so are stories like the Three Musketeers, and sentences like this normally feel more complete if they follow the rule of three.
• Seven is the most popular number. It is the only single digit number, other than one, that isn’t a multiple or a factor of any other. There are seven visible planets, seven days in a week, and seven deadly sins. Seven is luck in the casinos of Las Vegas.
• 110 is the world’s least favourite number.

Read more on Nautilus.