2011205509 has 2 divisors, whose sum is σ = 2011205510. Its totient is φ = 2011205508.

The previous prime is 2011205473. The next prime is 2011205533. The reversal of 2011205509 is 9055021102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1276632900 + 734572609 = 35730^2 + 27103^2 .

It is a cyclic number.

It is not a de Polignac number, because 2011205509 - 2⁹ = 2011204997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2011205579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1005602754 + 1005602755.

It is an arithmetic number, because the mean of its divisors is an integer number (1005602755).

Almost surely, 2^2011205509 is an apocalyptic number.

It is an amenable number.

2011205509 is a deficient number, since it is larger than the sum of its proper divisors (1).

2011205509 is an equidigital number, since it uses as much as digits as its factorization.

2011205509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 2011205509 is about 44846.4659588690. The cubic root of 2011205509 is about 1262.2696785216.

The spelling of 2011205509 in words is "two billion, eleven million, two hundred five thousand, five hundred nine".