12185423491 has 4 divisors (see below), whose sum is σ = 12482628984. Its totient is φ = 11888218000.

The previous prime is 12185423477. The next prime is 12185423507. The reversal of 12185423491 is 19432458121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19432458121 = 2203 ⋅8820907.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12185423491 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12185423401) 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, 148602685 + ... + 148602766.

It is an arithmetic number, because the mean of its divisors is an integer number (3120657246).

Almost surely, 2^12185423491 is an apocalyptic number.

12185423491 is a deficient number, since it is larger than the sum of its proper divisors (297205493).

12185423491 is an equidigital number, since it uses as much as digits as its factorization.

12185423491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297205492.

The product of its digits is 69120, while the sum is 40.

The spelling of 12185423491 in words is "twelve billion, one hundred eighty-five million, four hundred twenty-three thousand, four hundred ninety-one".