11813468721 has 4 divisors (see below), whose sum is σ = 15751291632. Its totient is φ = 7875645812.

The previous prime is 11813468707. The next prime is 11813468729. The reversal of 11813468721 is 12786431811.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 11813468721 - 2⁷ = 11813468593 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11813468729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1968911451 + ... + 1968911456.

It is an arithmetic number, because the mean of its divisors is an integer number (3937822908).

Almost surely, 2^11813468721 is an apocalyptic number.

It is an amenable number.

11813468721 is a deficient number, since it is larger than the sum of its proper divisors (3937822911).

11813468721 is an equidigital number, since it uses as much as digits as its factorization.

11813468721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3937822910.

The product of its digits is 64512, while the sum is 42.

The spelling of 11813468721 in words is "eleven billion, eight hundred thirteen million, four hundred sixty-eight thousand, seven hundred twenty-one".