205204421 has 2 divisors, whose sum is σ = 205204422. Its totient is φ = 205204420.

The previous prime is 205204409. The next prime is 205204457. The reversal of 205204421 is 124402502.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 203205025 + 1999396 = 14255^2 + 1414^2 .

It is a cyclic number.

It is not a de Polignac number, because 205204421 - 2⁶ = 205204357 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 205204393 and 205204402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205204721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102602210 + 102602211.

It is an arithmetic number, because the mean of its divisors is an integer number (102602211).

Almost surely, 2^205204421 is an apocalyptic number.

It is an amenable number.

205204421 is a deficient number, since it is larger than the sum of its proper divisors (1).

205204421 is an equidigital number, since it uses as much as digits as its factorization.

205204421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 205204421 is about 14324.9579755055. The cubic root of 205204421 is about 589.8327793839.

Adding to 205204421 its reverse (124402502), we get a palindrome (329606923).

The spelling of 205204421 in words is "two hundred five million, two hundred four thousand, four hundred twenty-one".