223684540209 has 81 divisors (see below), whose sum is σ = 357138456129. Its totient is φ = 134848359360.

The previous prime is 223684540207. The next prime is 223684540301. The reversal of 223684540209 is 902045486322.

The square root of 223684540209 is 472953.

It is a perfect power (a square), and thus also a powerful number.

223684540209 is a `hidden beast` number, since 2 + 2 + 3 + 6 + 84 + 540 + 20 + 9 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 172278954225 + 51405585984 = 415065^2 + 226728^2 .

It is not a de Polignac number, because 223684540209 - 2¹ = 223684540207 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (223684540207) 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 80 ways as a sum of consecutive naturals, for example, 1235826099 + ... + 1235826279.

Almost surely, 2^223684540209 is an apocalyptic number.

223684540209 is the 472953-rd square number.

223684540209 is the 236477-th centered octagonal number.

It is an amenable number.

223684540209 is a deficient number, since it is larger than the sum of its proper divisors (133453915920).

223684540209 is an equidigital number, since it uses as much as digits as its factorization.

223684540209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528 (or 264 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 45.

The spelling of 223684540209 in words is "two hundred twenty-three billion, six hundred eighty-four million, five hundred forty thousand, two hundred nine".