243435221 has 2 divisors, whose sum is σ = 243435222. Its totient is φ = 243435220.

The previous prime is 243435161. The next prime is 243435263. The reversal of 243435221 is 122534342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 213568996 + 29866225 = 14614^2 + 5465^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243435221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243435271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121717610 + 121717611.

It is an arithmetic number, because the mean of its divisors is an integer number (121717611).

Almost surely, 2^243435221 is an apocalyptic number.

It is an amenable number.

243435221 is a deficient number, since it is larger than the sum of its proper divisors (1).

243435221 is an equidigital number, since it uses as much as digits as its factorization.

243435221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5760, while the sum is 26.

The square root of 243435221 is about 15602.4107432153. The cubic root of 243435221 is about 624.3974745810.

Adding to 243435221 its reverse (122534342), we get a palindrome (365969563).

The spelling of 243435221 in words is "two hundred forty-three million, four hundred thirty-five thousand, two hundred twenty-one".