204420421 has 2 divisors, whose sum is σ = 204420422. Its totient is φ = 204420420.

The previous prime is 204420407. The next prime is 204420467. The reversal of 204420421 is 124024402.

204420421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 204089796 + 330625 = 14286^2 + 575^2 .

It is a cyclic number.

It is not a de Polignac number, because 204420421 - 2⁹ = 204419909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (204420521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102210210 + 102210211.

It is an arithmetic number, because the mean of its divisors is an integer number (102210211).

Almost surely, 2^204420421 is an apocalyptic number.

It is an amenable number.

204420421 is a deficient number, since it is larger than the sum of its proper divisors (1).

204420421 is an equidigital number, since it uses as much as digits as its factorization.

204420421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 512, while the sum is 19.

The square root of 204420421 is about 14297.5669608504. The cubic root of 204420421 is about 589.0806528531.

Adding to 204420421 its reverse (124024402), we get a palindrome (328444823).

The spelling of 204420421 in words is "two hundred four million, four hundred twenty thousand, four hundred twenty-one".