204143243221 has 4 divisors (see below), whose sum is σ = 204309079744. Its totient is φ = 203977406700.

The previous prime is 204143243203. The next prime is 204143243233. The reversal of 204143243221 is 122342341402.

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 not a de Polignac number, because 204143243221 - 2⁷ = 204143243093 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 204143243221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204143243251) 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, 82916415 + ... + 82918876.

It is an arithmetic number, because the mean of its divisors is an integer number (51077269936).

Almost surely, 2^204143243221 is an apocalyptic number.

It is an amenable number.

204143243221 is a deficient number, since it is larger than the sum of its proper divisors (165836523).

204143243221 is a wasteful number, since it uses less digits than its factorization.

204143243221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165836522.

The product of its (nonzero) digits is 9216, while the sum is 28.

Adding to 204143243221 its reverse (122342341402), we get a palindrome (326485584623).

The spelling of 204143243221 in words is "two hundred four billion, one hundred forty-three million, two hundred forty-three thousand, two hundred twenty-one".