145545209 has 2 divisors, whose sum is σ = 145545210. Its totient is φ = 145545208.

The previous prime is 145545199. The next prime is 145545233. The reversal of 145545209 is 902545541.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 145274809 + 270400 = 12053^2 + 520^2 .

It is a cyclic number.

It is not a de Polignac number, because 145545209 - 2¹⁶ = 145479673 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (145545269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72772604 + 72772605.

It is an arithmetic number, because the mean of its divisors is an integer number (72772605).

Almost surely, 2^145545209 is an apocalyptic number.

It is an amenable number.

145545209 is a deficient number, since it is larger than the sum of its proper divisors (1).

145545209 is an equidigital number, since it uses as much as digits as its factorization.

145545209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36000, while the sum is 35.

The square root of 145545209 is about 12064.2119096110. The cubic root of 145545209 is about 526.0164242343.

It can be divided in two parts, 1455 and 45209, that added together give a palindrome (46664).

The spelling of 145545209 in words is "one hundred forty-five million, five hundred forty-five thousand, two hundred nine".