145 (number)

From Wikipedia, the free encyclopedia


Cardinal One hundred [and]
forty five
Ordinal 145th
Factorization 5 \cdot 29
Roman numeral CXLV
Binary 10010001
Hexadecimal 91

145 is the natural number following 144 and preceding 146.

[edit] In mathematics

Although composite, 145 is a pseudoprime.

Given 145, the Mertens function returns 0.

145 is a pentagonal number and a centered square number.

145 = 122 + 12 = 82 + 92. 145 is the fourth number that is the sum of two different pairs of squares. Also, 145 is the result of 34 + 43, making it a Leyland 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.

[edit] In other fields

For the year 145 AD, see 145.