145 is the natural number following 144 and preceding 146 .
Although composite, 145 is a pseudoprime.
Given 145, the Mertens function returns 0.
145 is a pentagonal number and a centered square number.
145 = 1! + 4! + 5!. The only other numbers that have the property that they are the sum of the factorials of their digits are 1, 2 and 40585 .
145 = 122 + 12 = 82 + 92. 145 is the fourth number that is the sum of two different pairs of squares.
For the year 145 AD, see 145.