204032100021 has 4 divisors (see below), whose sum is σ = 272042800032. Its totient is φ = 136021400012.

The previous prime is 204032100011. The next prime is 204032100023. The reversal of 204032100021 is 120001230402.

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 204032100021 - 2²² = 204027905717 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204032100023) 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, 34005350001 + ... + 34005350006.

It is an arithmetic number, because the mean of its divisors is an integer number (68010700008).

Almost surely, 2^204032100021 is an apocalyptic number.

It is an amenable number.

204032100021 is a deficient number, since it is larger than the sum of its proper divisors (68010700011).

204032100021 is an equidigital number, since it uses as much as digits as its factorization.

204032100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68010700010.

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 204032100021 its reverse (120001230402), we get a palindrome (324033330423).

The spelling of 204032100021 in words is "two hundred four billion, thirty-two million, one hundred thousand, twenty-one".