1311309 has 10 divisors (see below), whose sum is σ = 1958990. Its totient is φ = 874152.

The previous prime is 1311307. The next prime is 1311311. The reversal of 1311309 is 9031131.

It is an interprime number because it is at equal distance from previous prime (1311307) and next prime (1311311).

It can be written as a sum of positive squares in only one way, i.e., 1108809 + 202500 = 1053^2 + 450^2 .

It is not a de Polignac number, because 1311309 - 2¹ = 1311307 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1311291 and 1311300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 8014 + ... + 8175.

It is an arithmetic number, because the mean of its divisors is an integer number (195899).

2^1311309 is an apocalyptic number.

It is an amenable number.

1311309 is a deficient number, since it is larger than the sum of its proper divisors (647681).

1311309 is an equidigital number, since it uses as much as digits as its factorization.

1311309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16201 (or 16192 counting only the distinct ones).

The product of its (nonzero) digits is 81, while the sum is 18.

The square root of 1311309 is about 1145.1240107517. The cubic root of 1311309 is about 109.4548509682.

Adding to 1311309 its product of nonzero digits (81), we get a triangular number (1311390 = T₁₆₁₉).

The spelling of 1311309 in words is "one million, three hundred eleven thousand, three hundred nine".