243420441221 has 4 divisors (see below), whose sum is σ = 244046201100. Its totient is φ = 242794681344.

The previous prime is 243420441203. The next prime is 243420441241. The reversal of 243420441221 is 122144024342.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 90308664196 + 153111777025 = 300514^2 + 391295^2 .

It is a cyclic number.

It is not a de Polignac number, because 243420441221 - 2⁶ = 243420441157 is a prime.

It is a super-2 number, since 2×243420441221² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243420441241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 312879356 + ... + 312880133.

It is an arithmetic number, because the mean of its divisors is an integer number (61011550275).

Almost surely, 2^243420441221 is an apocalyptic number.

It is an amenable number.

243420441221 is a deficient number, since it is larger than the sum of its proper divisors (625759879).

243420441221 is an equidigital number, since it uses as much as digits as its factorization.

243420441221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 625759878.

The product of its (nonzero) digits is 12288, while the sum is 29.

Adding to 243420441221 its reverse (122144024342), we get a palindrome (365564465563).

The spelling of 243420441221 in words is "two hundred forty-three billion, four hundred twenty million, four hundred forty-one thousand, two hundred twenty-one".