# All Science Fair Projects

## Science Fair Project Encyclopedia for Schools!

 Search    Browse    Forum  Coach    Links    Editor    Help    Tell-a-Friend    Encyclopedia    Dictionary

# Science Fair Project Encyclopedia

For information on any area of science that interests you,
enter a keyword (eg. scientific method, molecule, cloud, carbohydrate etc.).
Or else, you can start by choosing any of the categories below.

# 169 (number)

169 is the natural number following one hundred sixty-eight and preceding one hundred seventy.

169
Cardinal one hundred [and]
sixty-nine
Ordinal169th
Factorization169 = 132
Roman numeralCLXIX
Binary10101001

One hundred sixty-nine is one of the few squares to also be a centered hexagonal number. But like any other odd square, it is also a centered octagonal number.

It is a Pell number.

It is the sum of seven consecutive primes, 13 + 17 + 19 + 23 + 29 + 31 + 37.

It is the number of nonequivalent starting hands in Texas hold 'em (see http://www.math.sfu.ca/~alspach/art3.pdf for an explanation).