204030021221 has 16 divisors (see below), whose sum is σ = 225817128768. Its totient is φ = 183143203200.

The previous prime is 204030021203. The next prime is 204030021233. The reversal of 204030021221 is 122120030402.

It is a cyclic number.

It is not a de Polignac number, because 204030021221 - 2¹⁸ = 204029759077 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 204030021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204030021281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 459815 + ... + 787076.

It is an arithmetic number, because the mean of its divisors is an integer number (14113570548).

Almost surely, 2^204030021221 is an apocalyptic number.

It is an amenable number.

204030021221 is a deficient number, since it is larger than the sum of its proper divisors (21787107547).

204030021221 is a wasteful number, since it uses less digits than its factorization.

204030021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1247252.

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 204030021221 its reverse (122120030402), we get a palindrome (326150051623).

The spelling of 204030021221 in words is "two hundred four billion, thirty million, twenty-one thousand, two hundred twenty-one".