145 (number)

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<< 140 141 142 143 144 145 146 147 148 149 >> List of numbers — Integers ← 100 110 120 130 140 150 160 170 180 190 →
Cardinal	One hundred [and] forty five
Ordinal	145th
Factorization
Divisors	1, 5, 29, 145
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.

[edit] References

• Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1987): 140