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odd, composite, triangular · 45th positive integer

The number 45

45 is an odd composite number. It is the 45th positive integer.

Quick reference

Prime factorization3 × 3 × 5
Divisors1, 3, 5, 9, 15, 45
Binary101101
Hexadecimal0x2D
Roman numeralXLV
Digit sum9
Propertiesodd, composite, triangular

Frequently asked

Is 45 a prime number?

No. 45 is composite. Its prime factorization is 3 × 3 × 5.

What are the factors of 45?

The factors (divisors) of 45 are 1, 3, 5, 9, 15, 45.

What is 45 in binary?

45 in binary is 101101. In hexadecimal it's 2D.

What is 45 as a Roman numeral?

45 in Roman numerals is XLV.

What's the digit sum of 45?

Adding the digits of 45: 4 + 5 = 9.

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