1011209209 has 2 divisors, whose sum is σ = 1011209210. Its totient is φ = 1011209208.

The previous prime is 1011209197. The next prime is 1011209219. The reversal of 1011209209 is 9029021101.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1011049209 + 160000 = 31797^2 + 400^2 .

It is an emirp because it is prime and its reverse (9029021101) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1011209209 - 2⁹ = 1011208697 is a prime.

It is not a weakly prime, because it can be changed into another prime (1011209219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 505604604 + 505604605.

It is an arithmetic number, because the mean of its divisors is an integer number (505604605).

Almost surely, 2^1011209209 is an apocalyptic number.

It is an amenable number.

1011209209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1011209209 is an equidigital number, since it uses as much as digits as its factorization.

1011209209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 25.

The square root of 1011209209 is about 31799.5158610945. The cubic root of 1011209209 is about 1003.7225285863.

The spelling of 1011209209 in words is "one billion, eleven million, two hundred nine thousand, two hundred nine".