12191688 has 32 divisors (see below), whose sum is σ = 33866400. Its totient is φ = 4063824.

The previous prime is 12191681. The next prime is 12191689. The reversal of 12191688 is 88619121.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (12191681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28006 + ... + 28437.

It is an arithmetic number, because the mean of its divisors is an integer number (1058325).

Almost surely, 2^12191688 is an apocalyptic number.

12191688 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

12191688 is an abundant number, since it is smaller than the sum of its proper divisors (21674712).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12191688 is a wasteful number, since it uses less digits than its factorization.

12191688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56458 (or 56448 counting only the distinct ones).

The product of its digits is 6912, while the sum is 36.

The square root of 12191688 is about 3491.6597772406. The cubic root of 12191688 is about 230.1554588576.

It can be divided in two parts, 121 and 91688, that added together give a square (91809 = 303²).

The spelling of 12191688 in words is "twelve million, one hundred ninety-one thousand, six hundred eighty-eight".