205306261 has 2 divisors, whose sum is σ = 205306262. Its totient is φ = 205306260.

The previous prime is 205306247. The next prime is 205306271. The reversal of 205306261 is 162603502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 156725361 + 48580900 = 12519^2 + 6970^2 .

It is a cyclic number.

It is not a de Polignac number, because 205306261 - 2¹⁵ = 205273493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205306271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102653130 + 102653131.

It is an arithmetic number, because the mean of its divisors is an integer number (102653131).

Almost surely, 2^205306261 is an apocalyptic number.

It is an amenable number.

205306261 is a deficient number, since it is larger than the sum of its proper divisors (1).

205306261 is an equidigital number, since it uses as much as digits as its factorization.

205306261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 205306261 is about 14328.5121697963. The cubic root of 205306261 is about 589.9303384190.

Adding to 205306261 its reverse (162603502), we get a palindrome (367909763).

The spelling of 205306261 in words is "two hundred five million, three hundred six thousand, two hundred sixty-one".