205309849 has 2 divisors, whose sum is σ = 205309850. Its totient is φ = 205309848.

The previous prime is 205309829. The next prime is 205309883. The reversal of 205309849 is 948903502.

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., 146894400 + 58415449 = 12120^2 + 7643^2 .

It is a cyclic number.

It is not a de Polignac number, because 205309849 - 2⁵ = 205309817 is a prime.

It is not a weakly prime, because it can be changed into another prime (205309829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102654924 + 102654925.

It is an arithmetic number, because the mean of its divisors is an integer number (102654925).

Almost surely, 2^205309849 is an apocalyptic number.

It is an amenable number.

205309849 is a deficient number, since it is larger than the sum of its proper divisors (1).

205309849 is an equidigital number, since it uses as much as digits as its factorization.

205309849 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 205309849 is about 14328.6373741539. The cubic root of 205309849 is about 589.9337750048.

The spelling of 205309849 in words is "two hundred five million, three hundred nine thousand, eight hundred forty-nine".