204023021 has 2 divisors, whose sum is σ = 204023022. Its totient is φ = 204023020.

The previous prime is 204023009. The next prime is 204023063. The reversal of 204023021 is 120320402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 199204996 + 4818025 = 14114^2 + 2195^2 .

It is a cyclic number.

It is not a de Polignac number, because 204023021 - 2¹⁸ = 203760877 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 204022987 and 204023005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (204023081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102011510 + 102011511.

It is an arithmetic number, because the mean of its divisors is an integer number (102011511).

Almost surely, 2^204023021 is an apocalyptic number.

It is an amenable number.

204023021 is a deficient number, since it is larger than the sum of its proper divisors (1).

204023021 is an equidigital number, since it uses as much as digits as its factorization.

204023021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 204023021 is about 14283.6627305464. The cubic root of 204023021 is about 588.6986745195.

Adding to 204023021 its reverse (120320402), we get a palindrome (324343423).

The spelling of 204023021 in words is "two hundred four million, twenty-three thousand, twenty-one".