205221281 has 2 divisors, whose sum is σ = 205221282. Its totient is φ = 205221280.

The previous prime is 205221259. The next prime is 205221319. The reversal of 205221281 is 182122502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 198246400 + 6974881 = 14080^2 + 2641^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205221281 is a prime.

It is a super-2 number, since 2×205221281² = 84231548350561922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (202221281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102610640 + 102610641.

It is an arithmetic number, because the mean of its divisors is an integer number (102610641).

Almost surely, 2^205221281 is an apocalyptic number.

It is an amenable number.

205221281 is a deficient number, since it is larger than the sum of its proper divisors (1).

205221281 is an equidigital number, since it uses as much as digits as its factorization.

205221281 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 23.

The square root of 205221281 is about 14325.5464468201. The cubic root of 205221281 is about 589.8489328831.

Adding to 205221281 its reverse (182122502), we get a palindrome (387343783).

It can be divided in two parts, 205221 and 281, that added together give a palindrome (205502).

The spelling of 205221281 in words is "two hundred five million, two hundred twenty-one thousand, two hundred eighty-one".