204042221 has 2 divisors, whose sum is σ = 204042222. Its totient is φ = 204042220.

The previous prime is 204042203. The next prime is 204042233. The reversal of 204042221 is 122240402.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 156625225 + 47416996 = 12515^2 + 6886^2 .

It is a cyclic number.

It is not a de Polignac number, because 204042221 - 2¹⁴ = 204025837 is a prime.

It is a super-2 number, since 2×204042221² = 83266455901225682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 204042221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (204042271) 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 as a sum of consecutive naturals, namely, 102021110 + 102021111.

It is an arithmetic number, because the mean of its divisors is an integer number (102021111).

Almost surely, 2^204042221 is an apocalyptic number.

It is an amenable number.

204042221 is a deficient number, since it is larger than the sum of its proper divisors (1).

204042221 is an equidigital number, since it uses as much as digits as its factorization.

204042221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 17.

The square root of 204042221 is about 14284.3348112539. The cubic root of 204042221 is about 588.7171408344.

Adding to 204042221 its reverse (122240402), we get a palindrome (326282623).

The spelling of 204042221 in words is "two hundred four million, forty-two thousand, two hundred twenty-one".