243023209 has 16 divisors (see below), whose sum is σ = 287711424. Its totient is φ = 202363200.

The previous prime is 243023201. The next prime is 243023213. The reversal of 243023209 is 902320342.

It is not a de Polignac number, because 243023209 - 2³ = 243023201 is a prime.

It is a super-2 number, since 2×243023209² = 118120560225315362, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (243023201) 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 in 15 ways as a sum of consecutive naturals, for example, 12247 + ... + 25219.

It is an arithmetic number, because the mean of its divisors is an integer number (17981964).

Almost surely, 2^243023209 is an apocalyptic number.

It is an amenable number.

243023209 is a deficient number, since it is larger than the sum of its proper divisors (44688215).

243023209 is a wasteful number, since it uses less digits than its factorization.

243023209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13128.

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 243023209 is about 15589.2016793677. The cubic root of 243023209 is about 624.0450132236.

The spelling of 243023209 in words is "two hundred forty-three million, twenty-three thousand, two hundred nine".