12191538 has 16 divisors (see below), whose sum is σ = 24677856. Its totient is φ = 4014720.

The previous prime is 12191507. The next prime is 12191563. The reversal of 12191538 is 83519121.

It is an unprimeable number.

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, 11743 + ... + 12738.

It is an arithmetic number, because the mean of its divisors is an integer number (1542366).

Almost surely, 2^12191538 is an apocalyptic number.

12191538 is an abundant number, since it is smaller than the sum of its proper divisors (12486318).

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

12191538 is a wasteful number, since it uses less digits than its factorization.

12191538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24569.

The product of its digits is 2160, while the sum is 30.

The square root of 12191538 is about 3491.6382974186. The cubic root of 12191538 is about 230.1545149505.

The spelling of 12191538 in words is "twelve million, one hundred ninety-one thousand, five hundred thirty-eight".