1311203513 has 4 divisors (see below), whose sum is σ = 1324185828. Its totient is φ = 1298221200.

The previous prime is 1311203483. The next prime is 1311203563. The reversal of 1311203513 is 3153021131.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 835614649 + 475588864 = 28907^2 + 21808^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311203513 - 2⁶ = 1311203449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1311203563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6491006 + ... + 6491207.

It is an arithmetic number, because the mean of its divisors is an integer number (331046457).

Almost surely, 2^1311203513 is an apocalyptic number.

It is an amenable number.

1311203513 is a deficient number, since it is larger than the sum of its proper divisors (12982315).

1311203513 is a wasteful number, since it uses less digits than its factorization.

1311203513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12982314.

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 1311203513 is about 36210.5442240240. The cubic root of 1311203513 is about 1094.5191589256.

Adding to 1311203513 its reverse (3153021131), we get a palindrome (4464224644).

The spelling of 1311203513 in words is "one billion, three hundred eleven million, two hundred three thousand, five hundred thirteen".