204122100421 has 4 divisors (see below), whose sum is σ = 204259372992. Its totient is φ = 203984827852.

The previous prime is 204122100389. The next prime is 204122100541. The reversal of 204122100421 is 124001221402.

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 204122100421 - 2⁵ = 204122100389 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 (204122103421) 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, 68634055 + ... + 68637028.

It is an arithmetic number, because the mean of its divisors is an integer number (51064843248).

Almost surely, 2^204122100421 is an apocalyptic number.

It is an amenable number.

204122100421 is a deficient number, since it is larger than the sum of its proper divisors (137272571).

204122100421 is a wasteful number, since it uses less digits than its factorization.

204122100421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137272570.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 204122100421 its reverse (124001221402), we get a palindrome (328123321823).

The spelling of 204122100421 in words is "two hundred four billion, one hundred twenty-two million, one hundred thousand, four hundred twenty-one".