11785384991 has 4 divisors (see below), whose sum is σ = 11787555672. Its totient is φ = 11783214312.

The previous prime is 11785384969. The next prime is 11785384993. The reversal of 11785384991 is 19948358711.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19948358711 = 31769 ⋅627919.

It is a cyclic number.

It is not a de Polignac number, because 11785384991 - 2²⁶ = 11718276127 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11785384993) 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, 1077176 + ... + 1088061.

It is an arithmetic number, because the mean of its divisors is an integer number (2946888918).

Almost surely, 2^11785384991 is an apocalyptic number.

11785384991 is a deficient number, since it is larger than the sum of its proper divisors (2170681).

11785384991 is an equidigital number, since it uses as much as digits as its factorization.

11785384991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2170680.

The product of its digits is 2177280, while the sum is 56.

The spelling of 11785384991 in words is "eleven billion, seven hundred eighty-five million, three hundred eighty-four thousand, nine hundred ninety-one".