243404123433221 has 2 divisors, whose sum is σ = 243404123433222. Its totient is φ = 243404123433220.

The previous prime is 243404123433161. The next prime is 243404123433337. The reversal of 243404123433221 is 122334321404342.

243404123433221 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., 150978011610721 + 92426111822500 = 12287311^2 + 9613850^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243404123433221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243404123483221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121702061716610 + 121702061716611.

It is an arithmetic number, because the mean of its divisors is an integer number (121702061716611).

Almost surely, 2^{243404123433221} is an apocalyptic number.

It is an amenable number.

243404123433221 is a deficient number, since it is larger than the sum of its proper divisors (1).

243404123433221 is an equidigital number, since it uses as much as digits as its factorization.

243404123433221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 331776, while the sum is 38.

Adding to 243404123433221 its reverse (122334321404342), we get a palindrome (365738444837563).

The spelling of 243404123433221 in words is "two hundred forty-three trillion, four hundred four billion, one hundred twenty-three million, four hundred thirty-three thousand, two hundred twenty-one".