204021021 has 8 divisors (see below), whose sum is σ = 272402080. Its totient is φ = 135826992.

The previous prime is 204020987. The next prime is 204021049. The reversal of 204021021 is 120120402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 204021021 - 2²⁵ = 170466589 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 204020988 and 204021006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204021121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44191 + ... + 48588.

It is an arithmetic number, because the mean of its divisors is an integer number (34050260).

Almost surely, 2^204021021 is an apocalyptic number.

It is an amenable number.

204021021 is a deficient number, since it is larger than the sum of its proper divisors (68381059).

204021021 is an equidigital number, since it uses as much as digits as its factorization.

204021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93515.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 204021021 is about 14283.5927203208. The cubic root of 204021021 is about 588.6967508785.

Adding to 204021021 its reverse (120120402), we get a palindrome (324141423).

The spelling of 204021021 in words is "two hundred four million, twenty-one thousand, twenty-one".