204021005 has 4 divisors (see below), whose sum is σ = 244825212. Its totient is φ = 163216800.

The previous prime is 204020987. The next prime is 204021049. The reversal of 204021005 is 500120402.

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 98465929 + 105555076 = 9923^2 + 10274^2 .

It is not a de Polignac number, because 204021005 - 2¹⁸ = 203758861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20402096 + ... + 20402105.

It is an arithmetic number, because the mean of its divisors is an integer number (61206303).

Almost surely, 2^204021005 is an apocalyptic number.

It is an amenable number.

204021005 is a deficient number, since it is larger than the sum of its proper divisors (40804207).

204021005 is an equidigital number, since it uses as much as digits as its factorization.

204021005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40804206.

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 204021005 is about 14283.5921602376. The cubic root of 204021005 is about 588.6967354893.

Adding to 204021005 its reverse (500120402), we get a palindrome (704141407).

The spelling of 204021005 in words is "two hundred four million, twenty-one thousand, five".