203243123221 has 4 divisors (see below), whose sum is σ = 203379621100. Its totient is φ = 203106625344.

The previous prime is 203243123207. The next prime is 203243123233. The reversal of 203243123221 is 122321342302.

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 77944822596 + 125298300625 = 279186^2 + 353975^2 .

It is a cyclic number.

It is not a de Polignac number, because 203243123221 - 2¹³ = 203243115029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (203243123201) 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, 68246706 + ... + 68249683.

It is an arithmetic number, because the mean of its divisors is an integer number (50844905275).

Almost surely, 2^203243123221 is an apocalyptic number.

It is an amenable number.

203243123221 is a deficient number, since it is larger than the sum of its proper divisors (136497879).

203243123221 is a wasteful number, since it uses less digits than its factorization.

203243123221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136497878.

The product of its (nonzero) digits is 3456, while the sum is 25.

Adding to 203243123221 its reverse (122321342302), we get a palindrome (325564465523).

The spelling of 203243123221 in words is "two hundred three billion, two hundred forty-three million, one hundred twenty-three thousand, two hundred twenty-one".