145 (number)

 ← 144 145 146 →
Cardinalone hundred forty-five
Ordinal145th
(one hundred forty-fifth)
Factorization5 × 29
Divisors1, 5, 29, 145
Greek numeralΡΜΕ´
Roman numeralCXLV
Binary100100012
Ternary121013
Quaternary21014
Quinary10405
Senary4016
Octal2218
Duodecimal10112
Vigesimal7520
Base 364136

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

In mathematics

• Although composite, 145 is a Fermat pseudoprime to sixteen bases with b < 145. In four of those bases, it is a strong pseudoprime: 1, 12, 17, and 144.
• 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: