243605321 has 2 divisors, whose sum is σ = 243605322. Its totient is φ = 243605320.

The previous prime is 243605309. The next prime is 243605353. The reversal of 243605321 is 123506342.

243605321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 208369225 + 35236096 = 14435^2 + 5936^2 .

It is a cyclic number.

It is not a de Polignac number, because 243605321 - 2¹⁰ = 243604297 is a prime.

It is a Chen prime.

It is equal to p_13348241 and since 243605321 and 13348241 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (243602321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121802660 + 121802661.

It is an arithmetic number, because the mean of its divisors is an integer number (121802661).

Almost surely, 2^243605321 is an apocalyptic number.

It is an amenable number.

243605321 is a deficient number, since it is larger than the sum of its proper divisors (1).

243605321 is an equidigital number, since it uses as much as digits as its factorization.

243605321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 26.

The square root of 243605321 is about 15607.8608720093. The cubic root of 243605321 is about 624.5428729907.

The spelling of 243605321 in words is "two hundred forty-three million, six hundred five thousand, three hundred twenty-one".