1311040243 has 4 divisors (see below), whose sum is σ = 1332532768. Its totient is φ = 1289547720.

The previous prime is 1311040219. The next prime is 1311040249. The reversal of 1311040243 is 3420401131.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1311040243 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1311040243.

It is not an unprimeable number, because it can be changed into a prime (1311040249) 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, 10746171 + ... + 10746292.

It is an arithmetic number, because the mean of its divisors is an integer number (333133192).

Almost surely, 2^1311040243 is an apocalyptic number.

1311040243 is a deficient number, since it is larger than the sum of its proper divisors (21492525).

1311040243 is an equidigital number, since it uses as much as digits as its factorization.

1311040243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21492524.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 1311040243 is about 36208.2897000121. The cubic root of 1311040243 is about 1094.4737274933.

Adding to 1311040243 its reverse (3420401131), we get a palindrome (4731441374).

The spelling of 1311040243 in words is "one billion, three hundred eleven million, forty thousand, two hundred forty-three".