# What Are Some Interesting Facts About the Number 30?

By Staff WriterLast Updated Apr 9, 2020 5:43:00 AM ET

Some interesting facts about the number 30 are that it is an even number that has eight factors, of which three are the prime numbers 2, 3 and 5. The prime factorization of 30 is 2 x 3 x 5. There are only 4 months in the calendar year that have 30 days, which are June, April, September and November.

Another math fact about the number 30 is that it is considered a pyramid number made up of the first four numbers such that 1^2 + 2^2 +3^2 + 4^2 equals 30. A pyramidal number corresponds to a set of points arranged in layers or stacks so that a square pyramid shape is formed. A pyramid number is also called a square pyramidal number.

Polygons that are 30-sided are known as tricontagons. Some polyhedra that contain 30 edges are an icosahedron and dodecahedron. If n is a number equal to or greater than 2, then n^5 - n can be divided by 30. For example, letting n = 3 in the given expression results in 243 - 3, which is equal to the number 240 and divisible by 30.

Some other interesting facts concerning 30 are that it is the sum of two primes that are consecutive, which are 13 and 17, and the sum of 1^2 + 2 ^2 + 5^2 is also equal to this number.