11685238891 has 4 divisors (see below), whose sum is σ = 11816533800. Its totient is φ = 11553943984.

The previous prime is 11685238883. The next prime is 11685238927. The reversal of 11685238891 is 19883258611.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19883258611 = 3823 ⋅5200957.

It is a cyclic number.

It is not a de Polignac number, because 11685238891 - 2³ = 11685238883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11685238871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65647321 + ... + 65647498.

It is an arithmetic number, because the mean of its divisors is an integer number (2954133450).

Almost surely, 2^11685238891 is an apocalyptic number.

11685238891 is a deficient number, since it is larger than the sum of its proper divisors (131294909).

11685238891 is an equidigital number, since it uses as much as digits as its factorization.

11685238891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131294908.

The product of its digits is 829440, while the sum is 52.

The spelling of 11685238891 in words is "eleven billion, six hundred eighty-five million, two hundred thirty-eight thousand, eight hundred ninety-one".