1311041243 has 4 divisors (see below), whose sum is σ = 1353332928. Its totient is φ = 1268749560.

The previous prime is 1311041227. The next prime is 1311041257. The reversal of 1311041243 is 3421401131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3421401131 = 193 ⋅17727467.

It is a cyclic number.

It is not a de Polignac number, because 1311041243 - 2⁴ = 1311041227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1311041203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21145796 + ... + 21145857.

It is an arithmetic number, because the mean of its divisors is an integer number (338333232).

Almost surely, 2^1311041243 is an apocalyptic number.

1311041243 is a deficient number, since it is larger than the sum of its proper divisors (42291685).

1311041243 is an equidigital number, since it uses as much as digits as its factorization.

1311041243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42291684.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 1311041243 is about 36208.3035090019. The cubic root of 1311041243 is about 1094.4740057643.

Adding to 1311041243 its reverse (3421401131), we get a palindrome (4732442374).

The spelling of 1311041243 in words is "one billion, three hundred eleven million, forty-one thousand, two hundred forty-three".