12187091 has 4 divisors (see below), whose sum is σ = 13928112. Its totient is φ = 10446072.

The previous prime is 12187073. The next prime is 12187117. The reversal of 12187091 is 19078121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19078121 = 769 ⋅24809.

It is a de Polignac number, because none of the positive numbers 2^k-12187091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12187051) 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, 870500 + ... + 870513.

It is an arithmetic number, because the mean of its divisors is an integer number (3482028).

Almost surely, 2^12187091 is an apocalyptic number.

12187091 is a deficient number, since it is larger than the sum of its proper divisors (1741021).

12187091 is an equidigital number, since it uses as much as digits as its factorization.

12187091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1741020.

The product of its (nonzero) digits is 1008, while the sum is 29.

The square root of 12187091 is about 3491.0014322541. The cubic root of 12187091 is about 230.1265277352.

The spelling of 12187091 in words is "twelve million, one hundred eighty-seven thousand, ninety-one".