204531421 has 2 divisors, whose sum is σ = 204531422. Its totient is φ = 204531420.

The previous prime is 204531419. The next prime is 204531443. The reversal of 204531421 is 124135402.

It is an a-pointer prime, because the next prime (204531443) can be obtained adding 204531421 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 185259321 + 19272100 = 13611^2 + 4390^2 .

It is a cyclic number.

It is not a de Polignac number, because 204531421 - 2¹ = 204531419 is a prime.

Together with 204531419, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 204531392 and 204531401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (204531401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102265710 + 102265711.

It is an arithmetic number, because the mean of its divisors is an integer number (102265711).

Almost surely, 2^204531421 is an apocalyptic number.

It is an amenable number.

204531421 is a deficient number, since it is larger than the sum of its proper divisors (1).

204531421 is an equidigital number, since it uses as much as digits as its factorization.

204531421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 204531421 is about 14301.4482133803. The cubic root of 204531421 is about 589.1872568811.

Adding to 204531421 its reverse (124135402), we get a palindrome (328666823).

The spelling of 204531421 in words is "two hundred four million, five hundred thirty-one thousand, four hundred twenty-one".