243421413221 has 4 divisors (see below), whose sum is σ = 278195900832. Its totient is φ = 208646925612.

The previous prime is 243421413149. The next prime is 243421413223. The reversal of 243421413221 is 122314124342.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243421413221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243421413223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17387243795 + ... + 17387243808.

It is an arithmetic number, because the mean of its divisors is an integer number (69548975208).

Almost surely, 2^243421413221 is an apocalyptic number.

It is an amenable number.

243421413221 is a deficient number, since it is larger than the sum of its proper divisors (34774487611).

243421413221 is an equidigital number, since it uses as much as digits as its factorization.

243421413221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34774487610.

The product of its digits is 9216, while the sum is 29.

Adding to 243421413221 its reverse (122314124342), we get a palindrome (365735537563).

The spelling of 243421413221 in words is "two hundred forty-three billion, four hundred twenty-one million, four hundred thirteen thousand, two hundred twenty-one".