243404003240221 has 2 divisors, whose sum is σ = 243404003240222. Its totient is φ = 243404003240220.

The previous prime is 243404003240173. The next prime is 243404003240249. The reversal of 243404003240221 is 122042300404342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128991329779225 + 114412673460996 = 11357435^2 + 10696386^2 .

It is a cyclic number.

It is not a de Polignac number, because 243404003240221 - 2²³ = 243403994851613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243404003240921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121702001620110 + 121702001620111.

It is an arithmetic number, because the mean of its divisors is an integer number (121702001620111).

Almost surely, 2^{243404003240221} is an apocalyptic number.

It is an amenable number.

243404003240221 is a deficient number, since it is larger than the sum of its proper divisors (1).

243404003240221 is an equidigital number, since it uses as much as digits as its factorization.

243404003240221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36864, while the sum is 31.

Adding to 243404003240221 its reverse (122042300404342), we get a palindrome (365446303644563).

The spelling of 243404003240221 in words is "two hundred forty-three trillion, four hundred four billion, three million, two hundred forty thousand, two hundred twenty-one".