1313021209 has 2 divisors, whose sum is σ = 1313021210. Its totient is φ = 1313021208.

The previous prime is 1313021207. The next prime is 1313021221. The reversal of 1313021209 is 9021203131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1220803600 + 92217609 = 34940^2 + 9603^2 .

It is an emirp because it is prime and its reverse (9021203131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1313021209 - 2¹ = 1313021207 is a prime.

Together with 1313021207, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1313021209.

It is not a weakly prime, because it can be changed into another prime (1313021207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656510604 + 656510605.

It is an arithmetic number, because the mean of its divisors is an integer number (656510605).

Almost surely, 2^1313021209 is an apocalyptic number.

It is an amenable number.

1313021209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1313021209 is an equidigital number, since it uses as much as digits as its factorization.

1313021209 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 22.

The square root of 1313021209 is about 36235.6345190753. The cubic root of 1313021209 is about 1095.0246956198.

The spelling of 1313021209 in words is "one billion, three hundred thirteen million, twenty-one thousand, two hundred nine".