# 145 (number)

 ← 144 145 146 →
Cardinal one hundred forty-five
Ordinal 145th
(one hundred and forty-fifth)
Factorization 5 × 29
Divisors 1, 5, 29, 145
Roman numeral CXLV
Binary 100100012
Ternary 121013
Quaternary 21014
Quinary 10405
Senary 4016
Octal 2218
Duodecimal 10112
Vigesimal 7520
Base 36 4136

145 (one hundred [and] forty-five) is the natural number following 144 and preceding 146.

## 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.
• $145 = 12^2 + 1^2 = 8^2 + 9^2$. 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.
• $145 = 1! + 4! + 5!$, making it a factorion. 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 is also: