204015421 has 2 divisors, whose sum is σ = 204015422. Its totient is φ = 204015420.

The previous prime is 204015403. The next prime is 204015437. The reversal of 204015421 is 124510402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 174530521 + 29484900 = 13211^2 + 5430^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-204015421 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (204015481) 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, 102007710 + 102007711.

It is an arithmetic number, because the mean of its divisors is an integer number (102007711).

Almost surely, 2^204015421 is an apocalyptic number.

It is an amenable number.

204015421 is a deficient number, since it is larger than the sum of its proper divisors (1).

204015421 is an equidigital number, since it uses as much as digits as its factorization.

204015421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 204015421 is about 14283.3966898634. The cubic root of 204015421 is about 588.6913646165.

Adding to 204015421 its reverse (124510402), we get a palindrome (328525823).

The spelling of 204015421 in words is "two hundred four million, fifteen thousand, four hundred twenty-one".