1311020209 has 4 divisors (see below), whose sum is σ = 1338914304. Its totient is φ = 1283126116.

The previous prime is 1311020201. The next prime is 1311020233. The reversal of 1311020209 is 9020201131.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1311020209 - 2³ = 1311020201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1311020201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13946977 + ... + 13947070.

It is an arithmetic number, because the mean of its divisors is an integer number (334728576).

Almost surely, 2^1311020209 is an apocalyptic number.

It is an amenable number.

1311020209 is a deficient number, since it is larger than the sum of its proper divisors (27894095).

1311020209 is an equidigital number, since it uses as much as digits as its factorization.

1311020209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27894094.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 1311020209 is about 36208.0130495999. The cubic root of 1311020209 is about 1094.4681525823.

The spelling of 1311020209 in words is "one billion, three hundred eleven million, twenty thousand, two hundred nine".