243033221 has 2 divisors, whose sum is σ = 243033222. Its totient is φ = 243033220.

The previous prime is 243033191. The next prime is 243033229. The reversal of 243033221 is 122330342.

243033221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 241180900 + 1852321 = 15530^2 + 1361^2 .

It is a cyclic number.

It is not a de Polignac number, because 243033221 - 2¹⁰ = 243032197 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 243033193 and 243033202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243033229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121516610 + 121516611.

It is an arithmetic number, because the mean of its divisors is an integer number (121516611).

Almost surely, 2^243033221 is an apocalyptic number.

It is an amenable number.

243033221 is a deficient number, since it is larger than the sum of its proper divisors (1).

243033221 is an equidigital number, since it uses as much as digits as its factorization.

243033221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 20.

The square root of 243033221 is about 15589.5227957754. The cubic root of 243033221 is about 624.0535828480.

Adding to 243033221 its reverse (122330342), we get a palindrome (365363563).

The spelling of 243033221 in words is "two hundred forty-three million, thirty-three thousand, two hundred twenty-one".